Sauté the onion and carrot in a pan with olive oil until soft.
Add the red lentils, spices, and salt. Cover with water (about 2 cups) and simmer for 12–15 minutes until the water is absorbed and lentils are tender.
While lentils cook, sear the halloumi slices in a hot skillet with a drop of oil for 2 minutes per side until golden.
Place a bed of lamb's lettuce on a plate, top with the warm lentil stir-fry, and finish with the grilled halloumi slices. Serve immediately.