One of the best things about Pico de Gallo is how customizable it is—especially when it comes to heat. The spice level depends mainly on the type and amount of chili you use, usually jalapeños or serrano peppers. If you want a milder salsa, remove the seeds and inner ribs from the peppers (where most of the heat lives). For medium heat, leave in some seeds or use one whole pepper. You can always taste and adjust as you go—start light and build up the heat. Other key factors for great Pico de Gallo include using ripe tomatoes, fresh lime juice, and letting the mix sit for about 15 minutes…