Prepare the dressing. In a large mixing bowl, combine the lemon juice, garlic, salt, black pepper, and chili flakes (if using). Slowly drizzle in the olive oil while whisking continuously until the dressing becomes well blended and slightly thickened. Set aside to allow the flavors to develop.

Cook the lentils. Place the rinsed lentils in a saucepan and add enough water to cover them by about an inch. Add the bay leaf. Bring to a boil over medium-high heat, then reduce to a gentle simmer. Cover and cook for about 20–25 minutes, or until the lentils are tender but still hold their shape. Drain any excess liquid and discard the bay leaf.

Combine lentils with dressing. While the lentils are still warm, transfer them directly into the bowl with the prepared dressing. Stir gently so they absorb the lemony flavor as they cool. Let them sit for a few minutes.

Add vegetables and herbs. Once the lentils have cooled slightly (they can still be a bit warm), add: chopped cucumber, bell peppers, green onions, parsley, mint. Toss everything together until evenly combined.

Adjust and serve. Taste the salad and adjust seasoning if needed—add more salt, pepper, or lemon juice to suit your preference. Serve immediately, or refrigerate for later.