Bring a pot with water to a boil and cook potato cubes for about 5 minutes. Drain and set aside
Meanwhile heat 2-3 tbsp. olive oil in a pan over medium heat. Add chopped onion
Cook for about 2 minutes, then add garlic, tomato paste and cooked lentils
Cook for another minute before adding sieved tomatoes, water or vegetable broth, paprika, marjoram and basil
Cook for about 2-3 minutes
Add potato cubes and bring sauce to a boil. Season with salt and pepper and remove pan from heat
Add some olive oil to the botton of your baking dish, along with a bit of the lentil-potato sauce
Now add enough eggplant slices to cover the sauce and add more sauce on top of the eggplant slices. Repeat this process for about 2-3 times until no eggplant slices are left. Finish with a last layer of sauce to cover the slices
Bake in the oven for 10 minutes
In the meantime melt 2 tbsp. vegan margarine or butter in a small saucepan over medium-low heat. Once melted add flour and stir until no lumps remain. Add 1 1/2 cups of cold plant based milk. Reduce heat to low. Stir well
Add a generous pinch of nutmeg and season with salt and pepper
Bring bechamel to a boil (while stirring continuously)
Once it’s boiling, remove saucepan from heat
Remove the baking dish from the oven and add the bechamel sauce on top
Bake for another 40-50 minutes or until bubbly and hot