PROCESS: Add pine nuts, lemon juice, garlic, salt, and pepper into a food processor, pulsing to finely chop contents. Add basil, olive oil, and parmesan cheese (if using), continue to pulse until contents are combined. If you don't like the texture of the pesto sauce, add a teaspoon more of olive oil at a time to get a smoother texture. 1/2 cup toasted pine nuts, 1 tbsp garlic,, 2 tbsp lemon juice, 1/4 tsp salt, ground black pepper,, 2 cups fresh basil leaves, 1/4 cup olive oil, 1/3 cup parmesan cheese (optional),