Bring a large pot of salted water to a boil. Prepare the pasta according to the package instructions, cooking until al dente. Drain and toss with a drizzle of olive oil to prevent sticking. Heat the oil in a large, deep skillet over medium heat. Add the garlic, squash, zucchini, asparagus, tomatoes, onion, salt, and several grinds of pepper and sauté for 3 to 4 minutes, or until the vegetables are tender. Add the pasta, peas, cheese, lemon juice, and a pinch of red pepper flakes and toss to combine. Stir in the basil and tarragon, if using. Season to taste, garnish with more basil, and serve.