Pesto is basically a sauce originated from italy, prepared using pine nuts. Basil leaves, garlic, salt, parmesan cheese or pecorino sardo (cheese made from sheep's milk) blended using olive oil. Pesto is used in many veg, non-veg dishes. Pine nuts can be substituted with walnuts, cashew nuts, almonds, peanuts as these nuts have buttery, creamy texture. I tried this recipe with roasted walnuts as well. However, the basil pesto with roasted almonds tastes awesome.