It's tomato season -- put down that jar of store-bought salsa!
In a food processor, pulse onion, garlic, and jalapeno. Roughly chop tomatoes and add 2/3 of it to food processor. Pulse until chopped. Transfer to a bowl. Then pulse remaining 1/3 tomato until liquefied. Add to bowl with vinegar, oregano, and salt. Stir to combine.