If you're looking for an oil-free vegan pesto that doesn't skimp on flavor and richness, then I have a solution for you. This classic pesto recipe substitutes nutritional yeast for the parmesan and aquafaba for the oil. Bump up the nutrition with spinach and the brightness with lemon juice, and you have an absolutely decadent vegan pesto.
4 cups of tightly packed fresh basil is just a tad less than 3 oz. If you buy a big 3oz container of basil just use that and you won't have to measure.
If you don't have fresh basil, you can use a mixture of frozen basil and spinach, though the consistency might change slightly.
The ratio of spinach to basil is not set in stone. Feel free to use just basil and no spinach, or an equal amount of spinach and basil. I don't recommend using more spinach than basil, as you will start to lose flavor.
The pine nuts can be substituted for any kind of nuts or seeds you prefer, but walnuts, almonds, cashews, or sunflower seeds will work best.
Save the chickpeas from your aquafaba and add them to your pasta or save for another dish.