2 cups tightly packed fresh basil leaves
½ cup extra virgin olive oil
3 TBSP pine nuts
2 garlic cloves, chopped fine before going in the processor
Salt
1/3 cup freshly grated Pamigiano-Reggiano cheese
2 TBSP freshly grated Romano cheese
3 TBSP butter, softened to room temperature
1.5 pounds Pasta
Transfer to a bowl, and mix in the two grated cheeses by hand. (It is worth the slight effort to do it by hand to obtain the notably superior texture it produces.)
When the cheese has been evenly amalgamated with the other ingredients, mix in the softened butter, distributing it uniformly into the sauce.