1-In a large saucepan, combine the lentils,: In a large saucepan, combine the lentils, water or broth, and bay leaf. Bring to a boil over medium high heat and then turn to low and cook for 15 to 20 minutes or until lentils are soft, but still slightly firm. Do not overcook or the lentils will be mushy.
2-While the lentils are cooking, make the: While the lentils are cooking, make the dressing. In a small bowl or jar, whisk together the olive oil, lemon zest, lemon juice, Dijon mustard, honey or maple syrup, garlic, salt, and pepper. Set aside.
3-When the lentils are done cooking, use: When the lentils are done cooking, use a colander to drain the lentils. Discard the bay leaf. Rinse quickly with cold water. Transfer to a large bowl.
4-Add the cucumber, red pepper, red onion,: Add the cucumber, red pepper, red onion, parsley, mint, and feta cheese, if using, to the bowl. Stir. Drizzle with dressing and toss until well combined. Serve immediately or let sit for 30 minutes so the flavors can meld.