Dice the vegetables, and slice the sausage. Grate your cheese, and break the eggs into a large bowl.
Make the Frittata
Pre cook the sausage in an oven safe skillet (we used a cast iron pan) until it gets lovely brown marks on it. Add the peppers and onions and cook until soft.
Beat the eggs with the milk, and season with salt and pepper, and add to the pan.
Add the egg mixture to the pan, lower the heat and cook until the bottom is set (top will still be jiggly)
Broil
Sprinkle with cheese, and put under the broiler, and cook until brown on top and the eggs are set.
Pull it out, cut it in wedges and serve. (I run a knife around the outside first).