Bring a medium-sized pot of water to a boil on the stove. Simmer lentils on low-medium heat in a covered pot for approximately 20 minutes until tender.
While lentils are cooking, finely chop the tomato, cucumber, shallot, parsley, and mint and add to a big bowl.
Drain the lentils when finished cooking. Once cooled, add them to the bowl along with the lemon juice, lemon zest, olive oil, salt, and pepper. Stir together and enjoy!