Add nuts, garlic powder, nutritional yeast, mustard, lemon juice and olive oil to food processor, and pulse until combined.
Run processor while you slowly add in water until the mixture is the desired consistency (about 3 tbs - 1/4 cup water). Scrape down the sides and pulse again to make sure the dressing is smooth. Season to taste with salt and pepper.
Tastes great straight away, or chill first for a stronger flavor.