Begin by bringing a large pot of salted water to a rolling boil.

While waiting for the water, pulse the pistachios until coarsely chopped, then add pecorino, lemon juice, salt, black pepper, and basil leaves and blend while drizzling in olive oil.

In a skillet over low heat, melt butter and remaining olive oil, then add minced garlic and sauté for about 2 minutes.

Add the ravioli to the boiling water and cook for about 3 minutes until they float, reserving 1/2 cup of cooking water before draining.

In the skillet, combine sautéed garlic and pesto, then gently toss in the drained ravioli with reserved cooking water.

Serve immediately, garnished with black pepper and optional red pepper flakes.