Nutrition information per serving: 260 calories; 17 g fat; 7 g saturated fat; 255 mg cholesterol; 350 mg sodium; 9 g carbohydrate; 3 g fiber; 17 g protein
For the eggs: Preheat the oven to 350°F. Whisk the eggs and ¼ cup of Parmesan cheese together in a large bowl. Season with salt and pepper as desired. Set aside.
In a cast iron pan, heat the olive oil and add the scallions, shallots, and cook 1 minute over medium heat. Add the zucchini and cook until they start to color. Add the Swiss chard and cook until wilted. Add thyme, pepper flakes, and cook to combine.
Add the bell peppers, asparagus, and salt to taste, and cook, stirring occasionally, until the asparagus are soft but still al dente, reduce heat and cook until completely tender.
Gently stir in the spinach, stirring often, until the spinach wilts. Increase the heat to medium-high and cook until most of the liquid is evaporated, stirring often, for about 2 to 6 minutes.
To prep the tomatoes and basil: Lay the tomato slices on a piece of paper towel. Cover with another paper towel and gently press to absorb extra moisture and set aside.
Pour the eggs over the vegetables, and reduce heat to low. Cook until you can see that the eggs are setting on top of the vegetables, about 5 minutes. Garnish top of eggs with tomato slices, and top each tomato with a basil leaf and slice of mozzarella.
Stack remaining 8 basil leaves, roll lengthwise, and cut crosswise into thin strips. Sprinkle basil and remaining Parmesan over the top of the frittata. Bake until the top of the frittata is browned and puffy, about 15 minutes. Remove it from the oven and let cool for a few minutes. Slice and serve immediately.