Cook the lentils according to the package directions. For most brown lentils, bring 3 cups of water to boil in a pot, add the lentils, then continue to boil for 20 minutes, or until the lentils are tender. Drain the lentils in a colander and rinse briefly with cool water until they are cooled.

While the lentils are cooking, prepare the lemon garlic dressing. Use a microplane, zester, or small-holed cheese grater to remove about 1 Tbsp of the lemon's zest (the thin, yellow, outer layer of the peel). Set the zest aside. Juice the lemon and measure 1/4 cup of the juice to use for the dressing. In a small bowl, whisk together the lemon juice, olive oil, minced garlic, oregano, salt, and some freshly cracked pepper. Set the dressing aside.

When the lentils are cooked, cooled, and well drained, transfer them to a large bowl. Add the chopped parsley, tomatoes, red onion, cucumber, crumbled feta, lemon zest, and the prepared dressing. Stir to combine the ingredients and coat everything in dressing.

Serve immediately, or refrigerate until ready to eat. Always stir the salad just before serving to redistribute the dressing and flavors.