Preheat oven to 350F
Cut the broccoli into small florets and steam until just tender, let cool. At the same time, saute the onion or leek in olive oil, 3-4 minutes, over medium heat. Add the peppers and mushrooms and season with salt and pepper. Keep sauteing until tender.
While the veggies are cooking whisk (or blend in a blender) the eggs with the ricotta, cream, salt and pepper. ( Most any combo of ricotta, sour cream and cream will work here- 2 cups total.)
Grease a deep 9 x 13-inch baking dish or 12-inch skillet. Pour ½ of the egg mixture in the bottom. Add the cooked veggies (you should have roughly 6 cups). Add the basil, spinach and cheese and pour in the remaining egg mixture. Give the veggies and little swirl so egg mixture is incorporated.
In the middle of the oven until the center is puffed and the frittata is nice and golden about 1 hour. Check at 30-40 minutes and tent with foil if getting too dark.
You’ll know frittata is done with it puffs slightly at the very center and is not too wobbly.
Let stand 5 minutes before serving.
Leftovers keep 4 days in the fridge.