Classic Pico de Gallo

Bahan-bahan (4 porsi)

• 1 cup finely chopped white onion (about 1 small onion)
• 1 medium jalapeño or serrano pepper, ribs and seeds removed, finely chopped (decrease or omit if sensitive to spice, or add another if you love heat)
• ¼ cup lime juice
• ¾ teaspoon fine sea salt, more to taste
• 1 ½ pounds ripe red tomatoes (about 8 small or 4 large), chopped
• ½ cup finely chopped fresh cilantro (about 1 bunch)