Bring a small pot of water to a boil. Simmer the frozen peas for one minute, then drain well.
In a food processor, pulse the peas, almonds, cashews, basil, mint, and lemon until well combined. Scraping down the sides as necessary. Some small chunks are fine.
With the motor running, stream in the olive oil.
Scrape down the sides of the food processor bowl again, then stream in 1 tablespoon of hot pasta water at a time, until the pesto comes together. You want a thick sauce consistency—you most likely won't use all the water.
Season with red pepper flakes, black pepper, and salt, then blend again.
Meanwhile, boil the pasta in a medium-large pot until al dente. My pasta took about 7 minutes. Drain, and rinse if using chickpea pasta. Return the pasta to the pot.
While the pasta is cooking, heat 1 teaspoon olive oil in a medium-small nonstick skillet. Cook the zucchini, undisturbed, for two minutes. Then stir and cook one minute more. Remove from heat.
Gently fold the pesto into the cooked pasta, along with the sauteed zucchini, tomatoes, arugula, and feta. Taste, and adjust seasonings if you'd like.
Serve hot, warm, room temperature, or chilled.