Ingredients

• 1/2 cup finely chopped red onion
• 1-1/2 Tbs. fresh lime juice; more to taste
• 1/2 tsp. kosher salt
• 4 to 6 plums, split, pitted, and diced (to yield about 2 cups)
• 1 Tbs. finely chopped lemongrass
• 1 Tbs. chopped fresh mint
• 1 Tbs. chopped fresh basil
• 1 tsp. granulated sugar; more to taste
• 1 fresh jalapeño, cored, seeded, and finely chopped (optional)