Spring's seasonal produce is great not only because of its taste, but also because of how beautiful it all is. I used a basic frittata recipe as my canvas, and painted it with green, purple, and a little brown and white. Experiment with this recipe with what looks good in the produce aisle... or just follow it to a tee.
Preheat the oven to 450 degrees.
In a large, 12-inch ovenproof skillet with high sides, heat the olive oil and the butter over medium-high heat. Add the mushrooms and season with salt and pepper, to taste. Cook the mushrooms until all of their liquid has evaporated, about 8-10 minutes.
Add the onion and garlic and cook until the onion is translucent, about 5 more minutes. Add all of the asparagus except for the tips last and cook to heat through, about 1 minute.
Meanwhile, whisk all of the eggs together in a large bowl with the heavy cream and season with salt and pepper, to taste. Add 1 cup of the cheese to the egg mixture and give it a quick stir. Add the eggs to the skillet and stir so that the eggs and vegetables are well combined.
Cook the eggs, untouched, for about 5 minutes, until the sides are set. Right before you place the frittata in the oven, add the rest of the cheese and the asparagus tips to the top — do not stir. Cook the frittata until the top is golden brown and the middle is set, for 15-20 minutes.