Peel, core, and finely dice the half pineapple. You will have approximately 2 cups of pineapple chunks when done. Place in a medium bowl.
Seed and finely dice the serrano peppers. Add them to the pineapple. The exact heat of the pepper will vary, so add gradually until you reach your desired heat level.
Add the lime, red onion, cilantro, and a pinch of salt to the pineapple.
Mix to combine. Chill until ready to serve. This salsa is also fantastic on top of barbecued chicken or pork!
Notes
Serranos are like a thinner, spicier jalapeno. To tone down the heat you can use jalapeno instead. As with all peppers, the exact spiciness of a pepper is difficult to determine. Start with one pepper and add more as needed to reach your preferred heat level.