Place olive oil, pine nuts, salt and garlic in a blender. Purée, adding basil leaves a few at a time until the mixture becomes a thick paste.
Serving Suggestions: Add pesto, 1/4 cup fresh grated Parmesan, and 1/4 cup Pecorino Romano cheese to cooked spaghetti or other long pasta with 2 tbsp of pasta cooking water to emulsify.
Spread pesto on grilled vegetable or turkey-cheddar sandwiches.
Combine pesto with olive oil and use to marinate chicken before grilling.
Combine pesto with a vinaigrette for a pesto dressing, particularly good in salads with asparagus, corn, peaches, or nectarines.