Preheat oven to 425 degrees F. Line a baking sheet with a silicone mat.
Peel carrots and slice them thinly on the diagonal. In a bowl, toss sliced carrots with a 1/2 tablespoon of olive oil and a pinch of salt. Spread carrots on baking sheet and bake for 15 minutes, stirring after 10 minutes of baking. Remove from oven to cool.
In a pot, bring a quart of water to boil and add a generous pinch of salt. Add pasta and cook for 7 to 8 minutes. Rinse under cold water and set aside.
Rinse carrot tops thoroughly. In a food processor, blend all the carrot top pesto ingredients together. Taste to see if you need to add more salt.
Trim ends of zucchini and cut into noodles using a vegetable spiralizer or a julienne peeler. Set aside.
Heat 1 tablespoon of olive oil in a large sauté pan over medium heat. Add onions and cook until they soften, about 2 to 3 minutes. Add zucchini and cook for about 2 minutes. Turn off heat. Add pasta to pan and toss everything with 1/2 the pesto sauce. Feel free to add more sauce, if you like. Refrigerate remaining sauce for 1 to 2 days.
Top pasta with roasted carrots, parmesan, pepper, and a bit of lemon juice.
1. I like using 1 tablespoon of miso paste in my pesto, but you can replace that with 1/2 to 1 teaspoon of kosher salt.
2. Be sure to rinse the carrot tops thoroughly! I lot of dirt can get stuck in there!