Add the mushrooms and olive oil and season with salt and pepper. Cook for 8-10 minutes, or until the mushrooms have released all of their liquid, the liquid has evaporated, and the pan appears dry.

Stir in the spinach and cook for 2-3 more minutes, until any liquid from the spinach has cooked off. Make sure to cook as much moisture as possible out of the vegetables—you want them to appear dry. The freezing and reheating process will add moisture to the egg patty.

Transfer the vegetables to the prepared baking dish and spread them out into an even layer.

Whisk the eggs and milk in a large bowl until frothy. Carefully pour the egg mixture evenly over the vegetables.

Bake for 15-20 minutes, or until the eggs are completely set and begin to look a bit dry. Remove from the oven and cool completely.

When ready to assemble sandwiches, cut the egg and veggie “cake” into 12 even squares (or use a biscuit cutter or glass if you want round patties).

Assemble each sandwich by placing one patty on the bottom of one English muffin half. Top with two half-slices of bacon and one slice of cheese. Top with remaining half of muffin.

To freeze, wrap each sandwich tightly in plastic wrap and then store in a gallon freezer bag.

To reheat, unwrap the sandwich from plastic wrap. Wrap loosely in a paper towel and then heat in a microwave at 70% power for three minutes, until the cheese is melted and the sandwich is heated through. Microwaves can vary, so you may need to adjust the time.