Peel and dice the sweet potatoes into approximate 1/2-inch cubes. Dice the red bell pepper and chop the yellow onion. Mince the garlic.

Heat olive oil in a large (10-12 inch) skillet over medium-high heat. Add the ground turkey and cook, breaking it apart with a spoon, until it is browned and cooked through, about 5-7 minutes. Drain any excess fat from the skillet and transfer the cooked turkey to a plate; set aside.

In the same skillet (add a tiny bit more olive oil if needed), add the chopped onion and diced bell pepper. Cook for 5-7 minutes, stirring occasionally, until they begin to soften. Add the minced garlic and cook for another minute until fragrant.

Stir in the diced sweet potatoes, ground cumin, chili powder, smoked paprika, cayenne pepper (if using), salt, and black pepper. Cook for 2-3 minutes, stirring to coat the vegetables evenly with the spices.

Pour in the chicken or vegetable broth. Bring the mixture to a gentle simmer, then reduce the heat to medium-low, cover the skillet, and cook for 10-15 minutes, or until the sweet potatoes are tender when pierced with a fork. Stir occasionally to prevent sticking.

Return the cooked ground turkey to the skillet with the sweet potato mixture. Stir in the fresh spinach and cook just until it has wilted, about 1-2 minutes. Taste and adjust seasoning as needed.

Remove the skillet from heat. Garnish with fresh chopped cilantro or parsley, if desired, and serve warm.