Step 1

Heat the olive oil over medium-low heat in a large heavy pan. Add the onions and cook, stirring occasionally, for about 30 minutes. End goal: almost-jammy onions that are a reeeally deep, rich, golden brown. (Also, you probably smell like deliciously caramelizey onions now! New signature perfume?)

Step 2

Spinach: Toss the ham in a skillet with a quick drizzle of olive oil. Pan-fry until the edges are kind of browned and some of the fat is rendered. Throw in your spinach. Stir to wilt the spinach. Remove from heat.

Step 3

Whisk eggs with the milk, dijon, salt, and pepper.

Step 4

Preheat the oven to 350 degrees. Grease a 9×13 baking dish. Layer the ham, spinach, and onions on the bottom. Sprinkle with half of the cheese. Pour eggs over. Arrange croissant pieces on top. Finish with remaining cheese.

Step 5

Cover with foil. Bake for 30 minutes, depending on oven and pan size. Remove foil and bake for another 5-10 minutes. You don’t want to overcook the eggs (gross) but the middle should be almost completely firm when you give the pan a quick jiggle test. You’ll also notice the whole thing will be just starting to puff up a bit. Slice, serve, and brunch forward!