Dice the red onion and add it to a large mixing bowl with the lime juice.
Slice the top and bottom from your pineapple then slice the skin away and remove any eyes. Cut the pineapple down the middle then quarter and slice away the core. Dice into small pieces and place in a large bowl.
Dice the bell pepper, and tomatoes. Halve the jalapenos and remove the seeds and ribs then mince.
Mince cilantro leaves and place everything into the bowl with the pineapple. Sprinkle salt and stir to combine.
Notes
Make sure to cut all the fruit and vegetables to roughly the same size so you get a bit of everything in one bite.
Make sure to use fresh lime juice and not bottled stuff which is far too sour and acidic.
You can easily adjust the ingredients to taste for something more fruity why not replace the tomatoes with strawberries or for more savory flavors why not add in some fresh cucumber or avocado?
If you're not a fan of cilantro you can use fresh parsley instead, you must use fresh herbs and not dried.