Dice the tomatoes and cucumber into roughly 1-inch pieces. Place them in a large mixing bowl.
Crumble the feta cheese by hand over the vegetables. Irregular chunks work better than uniform crumbles.
In a small bowl, whisk together the olive oil, lemon juice, chopped parsley, and chopped mint until well combined.
Pour the dressing over the tomato-cucumber-feta mixture.
Gently toss everything together until evenly coated. Be careful not to overmix or the feta will break down too much.
Season with salt and pepper. Taste and adjust seasoning if needed—remember that feta is already salty.
Let the salad sit at room temperature for 5-10 minutes to allow the flavors to meld.
Serve immediately, or refrigerate for up to 2 hours if preparing ahead.