Preheat the oven to 350 degrees
First, you’ll want to saute the onions in butter until they’re slightly browned. Then, add mushrooms and peppers and cook for 2 more minutes. Throw in the spinach and tomatoes and cook it for another minute.
While the veggies are going, beat together eggs, cream, salt & pepper. Once the veggies are all cooked (according to step 2), add the egg mixture right on in.
Stir things up really good with a wooden spoon, and then add in all of the cheeses, the pine nuts, and the basil. Combine things well and make sure the eggs are even across the entire skillet.
Pop it in the oven and bake for about 15 minutes or until the center is firm.
Once you take it out of the oven, you’ll want to get it out of the skillet. I suggest taking a cookie sheet and putting it on top of the skillet, then flip it over. You may have to bang on the bottom of the skillet a few times to get it to all come loose.