1. Combine all ingredients in a small bowl.
This Latin-inspired salsa, which is primarily made of chopped red onion, chopped tomatillos, lemon juice, and extra-virgin olive oil, takes little time and effort to prepare. It's tasty and versatile enough to serve over grilled chicken and steak or with tacos and fajitas. For a tropical variation, try substituting chopped pineapple for the tomatillo.