Prep. Preheat oven to 375 F and grease a 9x13 casserole dish.
Cook sausage. Add breakfast sausage (1 pound) to a large skillet over medium heat. Break the meat into small pieces while the sausage cooks. Once browned and no longer pink, remove to a paper towel-lined plate.
Saute veggies. Carefully remove excess grease from the pan (I do this by tilting the pan, and dabbing up the grease with paper towels and a set of tongs), and add vegetable oil (2 tablespoons). Once shimmering, add chopped onions (1 cup), chopped bell peppers (1 cup), and salt (1 teaspoon). Saute until soft, about 10 minutes.
Eggs. In a large bowl, whisk eggs (10), heavy cream (1 cup), and tabasco (1/2 teaspoon). Stir in the shredded cheddar cheese (2 cups), cooled sausage, cooled cooked veggies, and sliced cherry tomatoes (1/2 cup). Pour into the prepared casserole dish.
Bake in the oven for 35-40 minutes. You'll know the casserole is done once the center is set and the edges begin to brown. Slice into 9 pieces, and enjoy!