Place cashews in a heatproof bowl, pour 1 cup of boiling water over them, and let stand for 10 minutes to 1 hour. Drain and dry thoroughly.
Add cashews and remaining ingredients to a small blender or food processor (see note 2). Add 1 tsp lime zest and 2 tbsp lime juice. Season with salt and pepper (I add 1/2 teaspoon salt and 1/4 teaspoon pepper). Blend until smooth.
Place in the fridge to chill and let the flavors meld. The sauce can be made ahead and refrigerated; just stir before serving. If it thickens, add a bit more lime juice to thin it.
Notes
Note 1: If you’d like a slightly sweeter sauce, add a drizzle of honey—perfect if your cilantro tastes a bit strong!Note 2: Either a blender or a food proccesor works geat, but to get an ultra-smooth sauce, use a high-powered blender. In the food processor, you’ll have a slightly chunkier sauce since the cashews don’t always break down as nicely.Nutrition Note: Nutrition information is based on the whole batch of sauce.Storage: Store leftover cilantro-lime sauce in an airtight container in the fridge for up to 5 days. Give it a quick stir before using.