One of those recipes you could eat every day - on tacos, salads, mixed with chickpeas to make a heartier salad, or with chips of course. Incredibly easy to throw together, simple whole ingredients, and absolutely delicious.
Dice the first five ingredients to roughly the same size and add to a mixing bowl. Use as much of each ingredient as you like. I typically do equal amounts tomatoes and mango with less of the pepper, cucumber, and onion. If unsure what you like, start with less and add more after mixing and tasting.
Chop as much cilantro as you like (I usually use one bunch for a large bowl) and mix with the other ingredients.
Mince jalapeño or other pepper if you want your salsa to have a kick of spice. Again, use to taste so start small and add more after tasting.
Juice enough limes to reach how tangy you like your salsa. How many you use will vary based on how juicy the limes are and how big the batch of salsa is. I generally start with two and add more if necessary after tasting.
Mix everything together with the salt and pepper. Taste. Assess flavor composition - sweet, sour, spice, etc. Adjust by adding more of the main ingredients like mango, more lime, or jalapeño if needed. The mango and veggies will release water and soften, and flavors will intensify and meld together as it sits, so I prefer to make the day before (or at least 3-4 hours) and taste the following day before adjusting.
Mince jalapeño or other spicy pepper if you want your salsa to have a kick of spice. Again, use to taste so start small and add more after tasting. If you've never worked with fresh hot peppers, I highly recommend using a glove when handling hot peppers and washing your knife and cutting board very well. I've experienced the pain of not doing so and rubbing my eye an hour later.