For the cilantro sauce, you will need sour-cream, yogurt or mayonnaise. I personally like to use sour-cream but whatever you have on hand will do! Combine about 1/4 cup fo sour-cream with 1/4 cup of cilantro, 1/2 a jalapeno, garlic, and zest of 1/2 lime in a food processor. The result is a spicy sauce that compliments the tacos and will make you keep coming back for more.