Begin by cooking the pasta. Add the fusilli to a large pan of boiling, salted water and cook for about 8 minutes (or according to packet instructions)
2
Meanwhile, make the pesto. De-stone the avocado and scoop the flesh into a blender or pestle and mortar. Add the lemon juice (but not zest), garlic, basil, olive oil, pecorino and walnuts and blend or grind until smooth
3
When the pasta is ready, drain and stir in the avocado pesto. Season with salt and pepper to taste and garnish with the lemon zest and walnuts