This is, or should be, a staple of grown-up summer vacation. It's a great way to make use of super-freshness: fish, tomatoes, and watermelon, especially. It's light and refreshing, and it keeps remarkably well in the fridge for a day or two. The watermelon is the surprise here, and it just piles on the summeriness, contrasting well, especially, if you turn up the jalopeño heat.

Ingredients

• 1 1/2 pounds fresh mild fish, such as striped bass, swordfish, or halibut
• 5 limes (just under 1 cup of juice)
• 1/4 cup red onion (or vidalia), chopped
• 1 jalapeño pepper, chopped finely (more or less to taste)
• 1 1/2 cups real, fresh tomato, chopped into cubes about 1/4" or a bit bigger
• 1 1/2 cups cucumber, chopped into cubes about 1/4" or a bit bigger
• 1 cup watermelon, chopped into cubes about 1/4" or a bit bigger
• 4 tablespoons fresh cilantro, chopped
• 1/4 cup good olive oil
• 1 pinch salt and pepper

Directions

1. Cut fish into flattened cubes, roughly 3/4" on a side. Mix in a bowl with the lime juice, onion, pepper, and salt (to taste, about 2 teaspoons of Maldon-style flakes). Make sure the fish is well-covered, and place in refrigerator to cure while you prepare the rest. Total cure time should be about 15 minutes, stirring every 5 minutes.
2. While the fish cures, combine the tomato, cucumber, watermelon, cilantro, and oil in a bowl. Add some salt and pepper. Mix gently but thoroughly.
3. After the fish is cured (all outside surfaces should be white and appear "cooked;" the fish should be sushi-quality), transfer it along with the lime mixture to the final serving bowl. Feel free to hold back some of the lime juice, which may seem excessive. If you prefer to be more cautious, you may cure the fish for a longer time in the lime juice in the fridge.
4. Pour the tomato mixture onto the fish and stir gently but thoroughly to combine well. Serve immediately, if desired with a crispy, starchy food. Corn chips would be obvious, but Finn Crisp is our favorite. Drink white beer with lemon with this for complete summer nirvana feeling.