Firstly, prepare the tomato sauce.Heat the olive oil in a large pan over medium-high heat.
Add the diced onion and garlic and fry until fragrant, 3-4 minutes. Next, add in the spices and herbs and cook for another minute, stirring.
Add in the chopped tomatoes and tomato puree, and season with salt and pepper to taste. Bring to boil and then reduce heat to low and simmer for 15-20 minutes until the sauce is reduced and thickens.
Preheat the oven to 355°F(180°C).Spread half of the tomato at the bottom of a baking dish.
Slice the sweet potatoes into 0.1″(3mm) thin slices and try to make each slice the same thickness.
Place a layer of sweet potato on the tomato sauce overlapping slightly—season with salt, herbs, and smoked paprika
Next, spread 1 can of black beans on top of the potato. Follow with another layer of sweet potato, and season with salt, herbs, and smoked paprika.Spread the second can of black beans followed with a third layer of sweet potato. Again season with salt, herbs, and smoked paprika.
Finally, top with the remaining tomato sauce. Cover with a piece of tin foil and bake for about 40-50 minutes, until the sweet potato is cooked through.
Sprinkle with grated vegan cheese and bake without cover for another 10-15 minutes, until the cheese has melted.