1. Pour boiling water over the peas, drain and process immediately with the basil, mint, cashews, garlic, cheese and olive oil to form a smooth pesto. Season to taste with salt and pepper.
2. Cook the pasta in salted water until al dente. Drain, but reserve a little of the pasta water. Mix the pasta immediately, while still hot, with the pesto. Add some of the cooking water if the pasta seems too dry.