Rinse the lentils and pick out any stones. Put them in a medium pot with the bay leaf and 6 cups of water, bring to a boil, then lower to a gentle simmer. Cook uncovered for 22 to 25 minutes, tasting from 20 minutes, until tender with a slight bite.

While the lentils simmer, make the vinaigrette. Mince the garlic and whisk it in a large bowl with the olive oil, red wine vinegar, oregano, salt, and pepper.

Dice the cucumber, halve the cherry tomatoes, dice the red bell pepper and red onion, and chop the parsley. Keep them in a separate bowl for now.

Drain the lentils well, discard the bay leaf, and spread them on a sheet pan for 3 to 4 minutes so they stop cooking and lose their steam.

Add the warm lentils to the vinaigrette and toss well. Let them sit for 5 minutes so they soak up the dressing while they are still warm.

Fold in the cucumber, tomatoes, bell pepper, red onion, and parsley.

Crumble the feta over the top and fold it in gently so it stays in pieces. Taste and add a splash more vinegar if it needs brightness.

Serve at room temperature, or chill in a sealed container. It is better after a few hours and keeps up to 5 days.