Kachumber Salad

1 small red onion, chopped
2 medium tomatoes, chopped
3 small cucumbers, chopped
10 mint leaves, chopped
¼ cup cilantro, chopped
1 tablespoon lemon juice
1 tablespoon olive oil
½ teaspoon cumin powder
1 jalapeno, minced or ¼ teaspoon red pepper flakes (optional)
sea salt to taste

Toss all ingredients together.