Before starting, I recommend overnight soaking & drying your sunflower seeds to reduce levels of antinutrients. Then pluck off & gather all your basil leaves, discarding stems.
Measure out 1 Cup of basil leaves, tightly packed, and add it to the bowl of your food processor.
Add the garlic, sunflower seeds, salt, sumac, and 1 Tablespoon of oil to the basil leaves. Put on the lid and pulse the ingredients for 15-20 seconds, until all the basil leaves have been lightly chopped and coated in oil. If you have a really high-powered food processor, you'll probably only need 2 Tablespoons of oil total.
Then slowly add in the rest of the oil and blend until smooth, about 1-2 minutes. Once done, your sunflower seed pesto is all ready to be used!
Notes
Basil. I have only tried this recipe with sweet basil, but you can use any varietal that tastes 'normal,' like Italian, Opal, Purple, or Large-Leaf Basil.Sun butter. If the thought of soaking and drying your sunflower seeds feels exhausting, you can use sun butter in their place, but only if it's a brand you've tolerated before & the only ingredient is sunflower seeds.Keeping it green. Commercial jarred pestos are usually made with basil that's been blanched— boiled for a few seconds, then immediately put on ice— in order to preserve their vibrant green color. Unfortunately this lessens their flavor tremendously, so while this sunflower seed pesto won't be as green as a store-bought one, it will be much more flavorful.