To a food processor, add the basil, kale, walnuts or hemp seeds (or both), garlic, lemon juice, nutritional yeast, and sea salt and blend until a paste/thicker consistency forms.
While the processor is blending, stream in the olive oil, 1 tbsp at a time, and scrape down sides as needed. Then begin to add 1 tbsp. of water at a time until you reach your desired consistency. You want it to be pourable so it will incorporate well into pasta or so it can be used as a marinade.
Adjust your sauce as needed or desired. More lemon for tang, more salt for enhanced flavour, more nutritional yeast for that thick, cheesy consistency and more nuts or seeds for that hearty, rich effect.
Notes
Pesto will last up to 1 week in a tightly sealed container in the fridge.Enjoy with your favourite pasta, use as a marinade or sauce for sandwiches!