Add ⅓ cup walnuts or pine nuts, 2 large garlic cloves roughly chopped, 1 teaspoon sea salt, and ¼ teaspoon freshly ground black pepper to food processor. Pulse 8 to 10 times until coarsely chopped.

Add 2 cups packed fresh basil leaves. Pulse 5 to 6 times until roughly combined with nut mixture.

With processor running, slowly drizzle in ½ cup extra-virgin olive oil through feed tube until well combined but mixture still has texture, about 30 seconds.

Add ½ cup grated Parmigiano-Reggiano cheese and ½ cup heavy cream. Pulse 3 to 4 times just until combined. For smoother consistency, add 1 to 2 tablespoons additional olive oil and pulse once more.