Halve roma tomatoes and scoop out seeds and core with a spoon.
Dice tomatoes into 1/4 inch pieces.
Finely dice white onion and mince jalapeño.
Combine tomatoes, onion, jalapeño, cilantro, and lime juice in a medium bowl.
Add a pinch of kosher salt and stir.
Let sit for 10-15 minutes to allow flavors to meld.
Taste and adjust salt, lime juice, or jalapeño as needed.
Serve with tortilla chips or use as a topping for tacos, nachos, or grilled meats.