Salsa Playera de Lujo (Fresh Tomato and Olive Salsa)

Ingredients

• 1 lb. ripe tomatoes, cored, seeded, and finely chopped
• ¼ cups finely chopped cilantro
• 2 tbsp. finely chopped pitted green olives
• 1 tbsp. finely chopped pickled jalapeños, plus 1½ tsp. liquid from jar
• 1 tbsp. capers, rinsed
• 1½ tsp. ketchup
• 1½ tsp. olive oil
• 1½ tsp. kosher salt
• ½ small white onion, minced