Wash veggies,and hands and have a clean space/cutting board.
When chopping Serrano, do not d-vein or remove seeds. It's what makes the heat! In a large bowl add chopped tomato, white onion, Serrano, salt, juice of lemons *limes*, cilantro, mix well and let stand for 10 minutes for juice to incorporate. Add to rice, or any meat as a side salsa. Enjoy!