Pineapple-Jicama Salsa

I made this once before and served it over grilled turbot. I'm not sure what recipe it was derived from, but there was so much leftover after the fish was gone I was content to eat it straight and call it a salad. This one ended up with more heat from only 1/2 a serrano than I expected, but I still found it to be nosh-able by itself. J whipped up some chicken & black bean tacos with it this afternoon. 

1 whole pineapple, peeled and diced

1 whole jicama (small), peeled and diced

1/2 serrano pepper (or less)

juice of 1 1/2 limes

1/4 chopped fresh cilantro

1/2 red onion, diced

Combine all ingredients in a bowl.