In the bowl of a stand mixer, combine the active sourdough starter, water, milk, and honey. Stir briefly until the starter is mostly dissolved.

Add the bread flour and salt.

Using the dough hook attachment, knead on medium-low speed for 7–10 minutes, or until the dough becomes smooth, elastic, and pulls away from the sides of the bowl. The dough should be soft and slightly tacky but not overly sticky.

Transfer the dough to a lightly greased bowl and cover.

Allow the dough to bulk ferment for 6–10 hours.

The exact timing will depend on the temperature and humidity of your kitchen. Rather than watching the clock, watch your dough. It should become noticeably puffy, feel airy, and increase in volume by about 50–75%.

For the best flavor and easier handling, place the covered dough in the refrigerator overnight.

If you'd rather continue the same day, you can move directly on to shaping after bulk fermentation.

Turn the dough onto a lightly floured work surface.

Roll it out to approximately 1 inch (2.5 cm) thick.

Using a biscuit cutter, cut out rounds, pressing straight down without twisting the cutter.

Place each round onto a parchment paper-lined baking sheet that has been generously dusted with cornmeal or semolina flour. Sprinkle additional cornmeal or semolina over the tops of the muffins as well.

Cover loosely with plastic wrap.

Allow the English muffins to rise for 2–4 hours, or until they appear puffy and have expanded slightly.

Again, the exact timing will vary depending on the warmth of your kitchen.

Preheat a cast iron skillet or heavy-bottomed skillet over low heat.

Carefully transfer the muffins to the skillet, leaving space between each one.

Cover with a lid and cook for 4–5 minutes on the first side.

Flip each muffin, remove the lid, and cook for another 4–5 minutes on the second side.

The English muffins are done when the centers reach an internal temperature of 200–205°F (93–96°C).

Between batches, brush or wipe away any excess cornmeal or semolina that remains in the skillet. This prevents it from burning and sticking to the bottoms of the next batch of muffins.