Bring a pot of water to a boil.

Blanch pine nuts, almonds, and walnut halves in boiling water briefly to remove skins.

Drain the nuts.

Combine blanched nuts, fresh basil, Italian parsley, grated Parmesan cheese, grated Romano cheese, garlic clove, and butter in a blender or food processor.

Pulse until coarsely chopped.

Slowly drizzle in olive oil while blending continuously until a smooth paste forms.

Transfer the pesto sauce to a large warm bowl.

Cook pasta until al dente according to package directions.

Using a fork, transfer the cooked pasta directly from the pot into the bowl with the pesto sauce.

Toss the pasta and pesto sauce thoroughly to coat.

Add 2 tablespoons of hot pasta water to the bowl.

Toss again to create a creamy sauce.

Serve immediately in hot soup bowls.