Start by preheating the oven to 350°F.
While the oven heats. Heat a well-seasoned cast-iron skillet on the stovetop. Sauté the chopped shallots in olive oil until it softens and slightly caramelized. Add the chopped veggies of your choice, cook until almost done, about 6-8 minutes for the veggies Ive recommended. Add the greens of your choice—baby spinach green parts of chard leaves or chopped kale—and cook just until they wil, (2-3 minutes) and there’s no liquid in the pan. If using bacon, sausages fully cook before adding the eggs.
Crack the eggs into a seperate bowl (1-2 per person). Whisk them together. Season with salt and pepper. If you like extra flavor paprika, chopped chives and/ or parsley. If you like cheese, add the grated cheese of your choice. I like a tablespoon of nutritional yeast for some B vitamin goodness. 1 tbsp for 8 eggs should work.
Spread out the veggies in the bottom of the oiled skillet. Make sure the oil coats the sides of the pan as well. Pour in the egg mixture evenly all around the veggies. Shake the pan gently if needed to even out.
Bake until it’s mostly set but still jiggles in the middle if you shake the pan. It will take anywhere from 20 to 25 minutes, depending how many eggs and kind of pan used. Err on the side of undercooking, there’s enough residual heat to cook through. Place it under the broiler for a minute or two if it doesn’t set when it cools.
Serve the frittata warm or at room temperature with some toasted rustic bread. Leftovers make excellent sandwich fillers. Toss together with some salad greens with a squeeze of lemon, a drizzle of olive oil, and fresh cracked pepper. Enjoy!!