Using a chef's knife and cutting board, dice the ripe seedless watermelon into roughly ½-inch cubes, then transfer to a large mixing bowl.
4 cups watermelon, diced
Finely chop the red onion and add it to the bowl with the watermelon, ensuring it is evenly distributed throughout the mixture.
1/2 small red onion, finely chopped
Chop fresh mint leaves into small pieces, then sprinkle over the mixture. Use a spoon to gently fold the mint into the other ingredients.
1/4 cup fresh mint leaves, chopped
Diced jalapeño pepper is added next; remove seeds beforehand if less heat is desired, then fold into the salsa mixture carefully.
1 piece jalapeño pepper, diced
Measure out lime juice and pour over the mixture, then sprinkle with salt to taste. Use a spoon to mix all ingredients thoroughly, ensuring flavors combine.
1 tablespoon lime juice, to taste salt
Allow the salsa to sit for 5-10 minutes in the refrigerator to allow flavors to meld, then serve chilled with chips or as a fresh topping.
