Use the chef's knife and cutting board to carefully dice the watermelon into roughly 1/2-inch cubes, ensuring even, bite-sized pieces.
4 cups watermelon, cubed
Finely chop the jalapeño, removing seeds if a milder heat is desired, until small pieces are formed and ready to be incorporated.
4 cups watermelon, cubed
In a mixing bowl, combine the chopped watermelon, jalapeño, lime juice, and chopped cilantro, stirring gently with a spoon to evenly distribute ingredients and coat everything with lime juice.
4 cups watermelon, cubed
Sprinkle salt over the mixture and stir again, allowing the flavors to meld for 5 minutes at room temperature.
4 cups watermelon, cubed
Taste the salsa and adjust salt or lime juice if necessary, then serve immediately or chill for up to 30 minutes for enhanced flavor melding.