In a medium bowl, whisk together fresh lemon juice, minced garlic, salt, black pepper, and chili flakes. Slowly drizzle in olive oil while whisking until emulsified.

Rinse lentils under cold water, combine with 3 cups of water in a pot, add a bay leaf, and boil. Reduce heat and simmer for 20-25 minutes until tender. Drain and cool slightly.

While lentils are warm, transfer to a mixing bowl and add the dressing, folding gently until well coated.

Mix in diced cucumber, chopped bell peppers, sliced green onions, and chopped parsley and mint. Toss gently.

Taste and adjust seasoning with salt, pepper, or lemon juice as needed. Serve at room temperature or chilled.