Cook pasta according to package instructions; reserve some pasta water and drain.
In a blender, combine fresh basil, garlic, nuts (pine nuts or cashews), olive oil, and a squeeze of lemon juice.
Blend until smooth to make pesto sauce.
Add salt and pepper to taste.
Toss cooked pasta with pesto sauce, adding a little reserved pasta water if needed.
Mix well until pasta is evenly coated.
Heat lightly if desired.
Garnish with extra herbs or nuts and serve.