In a large pan, heat olive oil over med-low heat and cook the onion and bell pepper until soft. Add the garlic and cook for 20-30 seconds (making sure not to burn the garlic). Mix in the ground turkey and add bay leaf, tomato sauce, wine, water, oregano, cumin, paprika, sugar, salt, and black pepper. Stir in the sweet potatoes, and continue cooking over medium heat, about 15 to 20 minutes, stirring occasionally, until the sweet potatoes are fork tender. If the sauce thickens too much, you can add a little bit more of water.