How to Make It
Spiralize the zucchini and yellow squash. If the zoodle strands are extremely long, cut the pile of zoodles in half.
Whisk together eggs with ½ cup whole milk. Season with kosher salt and black pepper.
Heat a large oven-safe skillet over medium and preheat your oven to 350ºF. Toss olive oil into the hot pan and add onion and minced garlic. Sauté for a few minutes, then toss in the prepared zoodles and sauté until cooked. Note that the zoodles may wilt a bit at they cook, so feel free to toss in more at this stage. Toss in chickpeas, sliced breakfast sausage, or cubed tofu, if using.
Pour the eggs into the pan with the vegetables and carefully transfer the pan to the oven. Bake the frittata for 25-30 minutes, or until just set. Top the frittata with a shower of pecorino cheese.