- In a pot, heat oil over medium-high heat. Add onion, celery, and zucchini.
- Sauté until vegetables are tender and water from zucchini has evaporated.
- Add tomatoes, chilli sauce, tomato paste, sugar, and pepper flakes.
- Season with salt and pepper. Reduce heat to medium-low and simmer, uncovered, for 25 minutes or until sauce thickens.
- Add lentils and herbs. Set aside.
- Preheat oven grill.
- With a basting brush, lightly oil the eggplant slices. Salt and pepper to taste.
- Place on a cookie sheet. Using top element in oven, grill for 4 minutes on each side.
- Repeat until all slices are cooked. Set aside.
- Preheat oven to 190°C (375°F).
- Cover the bottom of a lasagna dish measuring approximately 20 cm x 28 cm x 5 cm (8 in. x 11 in. x 2 in.), with a thin layer of tomato sauce. Cover with a layer of grilled eggplant.
- Pour in half the tomato sauce, then cover with another layer of grilled eggplant. Spread the ricotta cheese. Salt and pepper to taste. Cover with another layer of eggplant.
- Pour in the rest of the tomato sauce, then cover with a final layer of eggplant. Spread the grated cheese mix over top. Cook in oven for 25 minutes or until cheese is golden and sauce boils.
Variation: Serve lentil and vegetable tomato sauce on your favourite pastas for delicious vegetarian pasta dishes.