Heat 2 tablespoons of olive oil in a large stock pot over medium heat. Add red onion and bell peppers. Season with salt and black pepper, to taste. Cook, stirring occasionally, until soft and fragrant, about 4-5 minutes.

Add ½ teaspoon crushed red pepper flakes, 1 tablespoon ground cumin, 2 teaspoons chili powder, and ½ teaspoon dried oregano. Cook, stirring occasionally, for a minute or two until the spices become fragrant.

Add 2 large sweet potatoes (peeled and cubed), 6 ounces tomato paste, and 2 cans (15 ounces each) black beans (rinsed and drained). Season with additional salt and pepper, if desired, and stir to combine.

Add 6 cups vegetable broth and increase heat to medium-high. Bring to a boil, then immediately reduce to medium-low. Cover and simmer until the sweet potatoes are fork tender, about 15-20 minutes.

Stir in 1 cup frozen corn and heat for 2-3 minutes until warmed through. Top with ¼ cup chopped cilantro and 1 tablespoon fresh lemon juice and serve immediately.