Step 1

Coat a large skillet generously with olive oil. Add the onions and bring to a medium-high heat. Cook the onions until they are soft and very aromatic, about 8 to 10 minutes.

Step 2

Toss in the garlic and cook for 1 to 2 minutes.

Step 3

Toss in the spinach and cook for another 1 to 2 minutes. Turn off the heat and let cool.

Step 4

Crack the eggs into a large bowl. Toss in the coriander, nutmeg and pepper. Beat until the eggs are a smooth, homogeneous mixture.

Step 5

Whisk in the milk and cream. Beat until the mix is smooth and frothy.

Step 6

Toss in the bread cubes, cheeses, ham and cooked spinach mixture. Mix until everything is well-combined.

Step 7

Coat a 9- by 13-inch baking dish with olive oil.

Step 8

Transfer the egg mixture to the prepared dish. Cover with plastic and refrigerate overnight.

Step 9

Remove the casserole from the fridge. Let sit for 30 minutes to come to room temperature.

Step 10

Preheat the oven to 350 F.

Step 11

Bake the casserole for 30 minutes. Rotate the pan and bake for another 25 to 30 minutes or until the custard has set.

Step 12

Remove from the oven and let sit for 20 to 30 minutes before cutting and serving.