Rinse the lentils and place them in a pan with 2 cups of water. Bring the water to boil, reduce the heat and simmer for 20 minutes. In a large frying pan, heat the oil and add the garlic, chilli and sage and saute for a couple of minutes. Add the zucchini, lemon zest and capers to cook for 15 minutes, turning them over regularly. Add the smoked salmon pieces, lemon juice and pepper and heat through.
Drain the lentils and toss through the salmon and zucchini.