In a medium bowl, mix together diced pineapple, tomatoes, bell pepper, cilantro, red onion, serrano chilies, lime juice, salt and black pepper. Stir until well combined.
1 ¾ cups diced fresh pineapple, 1 cup diced tomatoes, ½ cup diced orange bell pepper, ⅓ cup chopped cilantro, ¼ cup diced red onion, 1 tablespoon diced serrano chili, 1 ½ tablespoons freshly squeezed lime juice, ¼ teaspoon kosher salt, ¼ teaspoon freshly ground black pepper