Like many frittata recipes, Andrew’s starts on the stovetop and finishes in the oven. In the recipe included below, the eggs cook entirely in the oven, moving it out of the frittata territory, making it more of an egg bake or a casserole. This recipe should be used as a guide and tailored to your tastes and preferences. I like a little bit of greens, a little bit of cheese, a little bit of onion, and a little bit of sausage, which makes the casserole feel a bit more substantial and precludes the need for cooking other breakfast meat on the side, which is especially nice when entertaining. Here’s a rough framework:
The Makings of A Very Nice Breakfast Casserole
Eggs: Estimate about 2 per person. Salt: A good rule of thumb: 1/2 teaspoon kosher salt for every 4 eggs. Something green. I like spinach, because it’s so low maintenance. No need to cook it — simply toss it with the hot sausage and onions, the heat of which will gently wilt it. Other options: roasted asparagus or broccoli, finely chopped Swiss chard or kale, etc. Cheese: I like Gruyère or Fontina. For 12 eggs, 4 ounces of grated cheese is about right. Onions: If you have the time to caramelize or near-caramelize an onion, do it. Otherwise, chopped scallions or chives will add that nice allium flavor, while also providing more green color. Sausage: I love hot Italian sausage here. The spices in the sausage flavor the custard, and the subtle spiciness is nice. Also: spinach + sausage is always a good match.
Breakfast casseroles or egg bakes are great for — wait for it — breakfast or brunch, especially when entertaining. But they also make great, low-key dinners, and the format can be used to clean out the odds and ends in your vegetable bins. Cold or re-heated, the leftover casserole makes a fine lunch on subsequent days, too. This is how I like to make this breakfast casserole: Start by browning the sausage. Pour it over a heap of spinach in a colander — this serves to both gently wilt the spinach and drain off excess fat and moisture. Caramelize or nearly caramelize an onion, if you wish. Transfer the onion to the colander as well. Toss to combine and further wilt the spinach. Transfer to a 9×13-inch pan and cover with grated cheese. (Love this 9×13-inch USA Pan.) Beat 12 eggs. Pour the eggs over top. Bake until custard is just set. 5 from 7 reviews Update: I’ve increased the oven temperature from 250ºF to 325ºF — when I made this most recently at the lower temperature it took way too long to cook, though my oven has been acting up. If you’ve had success at the lower temperature, go for it. Otherwise, try 325ºF, which will have this casserole done in just about 30 minutes. Also: I now add a cup of half and half. I think including some sort of milk product — milk, cream or half and half — makes the eggs more forgiving. When you overcook this casserole when it is eggs alone, it can be a bit rubbery tasting. When dairy is added, I find it remains more custardy. When I think about my favorite egg custard dish, Tartine’s Quiche, which calls for 2 cups of dairy (milk and crème fraîche) for 5 eggs, it makes me want to try this with yet another cup of half and half. I will be sure to report back when I do. Finally: When I make it vegetarian, I simply sauté the onions for about 10 minutes; then fold in the spinach just until it wilts. Then I proceed with the recipe as usual.
