Adult Grilled Cheese

You are going to love this three cheese grilled cheese sandwich! Sourdough bread, a trifecta of gooey Cheddar, Swiss, and Provolone cheese, and bacon with fried onions and tomatoes make this the ultimate grilled cheese sandwich! Pair it with creamy tomato soup for the perfect cozy comfort meal.

I. Love. Bread. Has Oprah trademarked that line yet? Just checked–we’re good, guys. Anyway, just like Oprah, I really do love bread. Guess what else I love? Yeah, you guessed it, cheese.

Now, there’s nothing wrong with a good old-fashioned grilled cheese. I eat those too. But sometimes, you want a little more, ya know? Something a bit more fancied up but still resembling that classic grilled cheese you know and love.

This is it, people. The ultimate adult grilled cheese sandwich. It has simple ingredients but when put together, the flavor is superior. You’re going to want to make this grown-up grilled cheese!

Why You’ll Love This Grown-Up Grilled Cheese

  • Provolone, Cheddar, and Swiss Cheese – This grilled cheese consists of three different cheeses that truly complement each other. Together, they are ooey-gooey and oh-so-delicious.
  • Fried Onions – Take a little time beforehand to grill the onions on your skillet, and you’ll be glad you did. They provide so much flavor to the sandwich and truly enhance the grilled cheese!
  • Bacon – The crisp bacon gives that added crunch to the sandwich. I highly recommend taking the time to cook the bacon in the oven or skillet beforehand! *However* you can omit the bacon if you’re low on time, don’t have any on hand, or don’t eat meat. It’s not necessary. Just very encouraged.
  • Sourdough Bread – Sourdough is my favorite bread to use for grilled cheese. Actually, it’s my favorite bread, period. It gives the loveliest crunch to this sandwich. It’s also a thick bread that can withstand all the ingredients packed in it.


These ingredients below are all you need to make the coziest and fanciest non-fancy grilled cheese!

  • Sourdough Bread – this is the BEST bread for grilled cheese, in my opinion. Any durable, thick bread will also do.
  • Cooked Bacon – nice and crispy is the best for this sandwich, but cook it to your preference.
  • Provolone, Swiss, and Cheddar Cheese – I chose these three because they are delicious together and also accessible at most grocery stores (and lower cost than the fancier cheeses)
  • Onions – (you’ll fry them as shown below) – I use white onion for this grilled cheese. I also like to add raw red onion to my grilled cheese occasionally.
  • Tomatoes – you’ll want a large tomato, such as beefsteak
  • Butter – to grill the sandwich on both sides

See recipe card for quantities.

Step-By-Step Instructions (With Video!)

Step 1: To start, preheat the oven to 400 degrees Fahrenheit. Cook the bacon for about 20 minutes (or until it reaches the level of crispiness you’re looking to achieve).

Step 2: Once cooked, put the bacon on top of a plate covered with paper towels to soak up the extra grease. Set aside while you prepare the rest of the ingredients.

Step 3: Slice the onion.

Step 5: Add 2 tablespoons of butter or olive oil to a skillet and set the stove to medium heat. Add the onions and cook until they are translucent–about 5-7 minutes. Move the onions to a plate while you prepare your grilled cheese.

Step 7: Add the cheese to the inside of the bread first. This will help meld together the rest of the ingredients!

Step 9: Grill the sandwich on both sides butter side down until golden brown.

Step 4: Slice the tomatoes.

Step 6: Butter the outside of sliced bread. Flip the bread over to add the ingredients.

Step 8: Assemble the rest of your grilled cheese! Add the bacon, tomatoes, and fried onions. If you want, you can throw another piece of cheese right in the middle before combining the two pieces of bread together.

Step 10: Enjoy along with a hearty bowl of tomato soup, or just on its own!

YouTube video

Hint: I prefer to cook with a cast iron skillet. You get the perfect amount of crispy-ness and crunchiness but any skillet will do!

Substitutions and Variations

There are so many ways to doctor up a grilled cheese sandwich! Truly, the possibilities are endless! Here are just a few substitutions:

  • Cheese – Cheddar, Provolone, and Swiss are just a few options. You could also try American, Monterey Jack, Pepperjack, Brie, Gouda, Gruyere, Fontina, chive-flavored cream cheese–like I said, endless possibilities.
  • Veggies- You could add avocado or guacamole, raw red onion, or omit the onions and tomatoes all together. Add basil, lettuce or kale, mushrooms–any vegetable you prefer could be worked into this sandwich.
  • Vegetarian – If you are vegetarian, you can omit the bacon.
  • Meat – Substitute the bacon for turkey, ham, or chicken.
close up of grown up grilled cheese with tomato soup in the background



I don’t recommend waiting to eat this later due to the fresh tomatoes and hot grilled ingredients. Besides, you won’t want to wait to eat this bad boy!

Top tip

You’ll more than likely have extra bacon. Save it for a BLT or another sandwich later in the week!


Do I have to use sourdough bread for this grilled cheese?

Nope! Though I highly recommend it, there are plenty of other good choices out there such as brioche, pumpernickel, ciabatta, Italian bread, and French bread. I suggest making sure whatever bread you choose is thick because this grilled cheese contains a lot of ingredients, and you want the bread to be sturdy.

How can I make this grilled cheese vegetarian?

Simple! Just omit the bacon.

Do I need all three types of cheeses? What if I use a different kind of cheese?

You do not need to use all three types if you don’t have them. Simply work with what you have. A grilled cheese is not a finnicky sandwich. It will still be delicious!

How can I fry the onions to perfection?

Make sure to peel the white onion first, then slice them as shown above! Add 2 tablespoons of either butter or olive oil to your skillet on medium heat. Then add the onions, being sure to break them apart a bit. It will take about 5-7 minutes to get them fried to perfection. They’ll be ready when they are translucent and maybe a little golden brown too! I like to use tongs to move them around as they cook, so they are evenly cooked through. The volume of the onions will decrease quite a bit compared to how they looked when they were raw. They are SO GOOD and add SO much flavor!

Can I make this sandwich in advance and reheat it later?

Grilled cheese is one of those sandwiches that are best enjoyed immediately after being cooked.

What should I eat with a grilled cheese sandwich?

The classic partner to grilled cheese is tomato soup! You could also try a different kind of soup, or choose to pair it with a salad to add some extra veggies in.

Looking for other recipes like this? Try these:

grown up grilled cheese

Grown-Up Grilled Cheese

This grown-up grilled cheese is a doctored-up version of the original classic. Gooey, melted Cheddar, Provolone, and Swiss cheese cover the fried onions, crisp bacon, and sliced tomatoes on this grilled cheese. Pair it with a bowl of tomato soup for the ultimate cozy meal!
5 from 1 vote
Print Pin Rate
Course: Dinner
Cuisine: American
Prep Time: 35 minutes
Cook Time: 7 minutes
Servings: 2
Calories: 693kcal
Author: Jamie


  • 4 slices sourdough bread
  • 2-4 slices of Cheddar cheese
  • 2-4 slices of Provolone cheese
  • 2-4 slices of Swiss cheese
  • 4 strips of crisp bacon
  • 1 white onion
  • 2 ripe tomatoes beefsteak or other big tomato
  • 6 tablespoons butter saving 2 tablespoons for frying the onions


  • To cook the bacon, set the stove to 400 degrees Fahrenheit. Lay parchment paper on a baking sheet and add the raw bacon on the sheet lined up next to each other. Cook for about 20 minutes or until the bacon has reached your desired amount of crispness. Once cooked, set the bacon on a plate covered with paper towels to soak up the excess grease. Set aside.
  • Peel and slice the onion. Slice the tomatoes. 
  • Heat a skillet on the stovetop over medium heat. Add two tablespoons of butter or olive oil. Add the onion to the skillet, combining it with the butter/oil in the skillet. Using a metal tong separate the onion slices from each other and cook until the onion is translucent and a little golden brown, or about 5-7 minutes.
  • Remove the onions from the skillet onto a plate while you assemble the grilled cheese.
  • Butter the outside of all slices of bread. Flip the bread over and add the Cheddar, Provolone, and Swiss cheese to both sides of each sandwich bread. It's up to your discretion whether you want to split each slice of cheese in half or add a full slice. 
  • Add the bacon slices, tomatoes, and fried onions. Before closing the sandwich together, add an extra slice or two of cheese if you wish. 
  • Place the sandwiches butter side down on the skillet and cook for about 2-3 minutes on each side, or until golden brown. 
  • Pair with tomato soup or a salad of your choice! Enjoy. 


Calories: 693kcal | Carbohydrates: 76g | Protein: 16g | Fat: 37g | Saturated Fat: 22g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 9g | Trans Fat: 1g | Cholesterol: 90mg | Sodium: 1049mg | Potassium: 532mg | Fiber: 5g | Sugar: 12g | Vitamin A: 2075IU | Vitamin C: 21mg | Calcium: 102mg | Iron: 5mg

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