Bake the Eggs – Preheat oven to 350°F. In a bowl, whisk eggs with milk, salt, and pepper. Pour into a greased 9x13-inch pan and bake 15–18 minutes, just until set. Let cool slightly, then cut into 12 squares.
Toast the Muffins – Split muffins, butter each side, and toast in the oven for 4–5 minutes until golden.
Cook the Protein – Lightly brown the ham slices (or your chosen meat) in a skillet.
Assemble – Place an egg square, a cheese slice, and your meat on the bottom half of each muffin. Top with the other half.
Melt & Serve – Bake the assembled sandwiches for about 4 minutes, until the cheese is gooey.
Freeze for Later – Wrap each cooled sandwich in parchment and foil. Freeze. To reheat, remove foil, microwave 60 seconds to defrost, then another 60 seconds to heat.