Bring a medium-large pot of salted water to a boil. Cook the spaghetti according to the package instructions, adding the frozen peas during the last minute of cooking. Reserve 1/4 cup hot pasta water, then drain the spaghetti and peas.
Meanwhile, heat the oil in a medium-large nonstick skillet. Saute the asparagus over medium heat until crisp-tender, adding the crushed pepper flakes to the pan during the last minute of cooking. My asparagus took about 4 minutes to cook, although this time will vary depending on the thickness of your asparagus and your pan.
When the asparagus and pasta/peas are done cooking, gently fold the pasta and peas directly into the asparagus pan. Season with the lemon juice and zest, adding hot pasta water as needed to help moisten the pasta. Fold in the nutritional yeast, panko, walnuts, basil, black pepper and salt. Taste and adjust the ingredients to your liking.
