Start by peeling and dicing the sweet potatoes into bite-sized cubes. Chop the onion and mince the garlic.

Heat 2 tablespoons of olive oil in a large pot over medium heat. Add the chopped onion and minced garlic; sauté for about 5 minutes until the onion is translucent and fragrant.

Toss in the diced sweet potatoes along with 1 teaspoon of cumin. Stir and sauté for an additional 3 minutes to let the spices infuse their flavor.

Stir in 1 cup of red lentils and 4 cups of vegetable broth. Bring the mixture to a boil, then reduce the heat to low, cover, and let it simmer for 20 minutes, until the lentils are tender.

In the last 5 minutes of cooking, add 2 cups of fresh spinach. Stir the stew until the spinach is wilted and bright green.

Taste your stew, then season with salt and pepper to your liking. Serve hot, optionally garnished with extra cumin for added depth of flavor.