Cook the gluten free pasta following pack instructions. Meanwhile, put the peppers, parsley, nuts, and garlic oil in a small food processor or mini chopper, and whizz to a pesto consistency. Season and mix in the Parmesan.
Drain the pasta and return to the pan with the pesto. Stir and gently heat for 1 min, then sprinkle with a little more chopped parsley and serve.