Step 1

Preheat the oven to 350 degrees F (175 degrees C).

Step 2

Heat coconut oil in a saucepan over medium-high heat. Add red onion, white onion, cinnamon, ginger, garlic, and 1 teaspoon cumin. Cook, stirring gently, until soft and tender, about 5 minutes. Add lentils, tomatoes, stock, and maple syrup. Bring to a boil; simmer filling until flavors are blended, 20 to 30 minutes.

Step 3

Place sweet potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until softened, about 20 minutes. Drain water; add coconut milk and remaining 1 teaspoon cumin to the sweet potatoes. Mash until smooth.

Step 4

Pour filling into a large baking dish; add the sweet potato mash on top and a sprinkle of nutritional yeast.

Step 5

Bake in the preheated oven until top is browned, about 20 minutes.