*To prevent curdling, don't skip the cornstarch. Use full fat yogurt and add to dish only when the sauce has cooled below simmer.
- Heat 2 tablespoons of the oil on high heat in a large saucepan. Add onions, bell peppers, garlic, celery, carrots and sweet potato; sauté until vegetables begin to soften and lightly brown. Remove the vegetables and set aside.
- Heat remaining 2 tablespoons of oil over high heat. Add turkey and sear for 3 to 4 minutes, stirring often, until turkey begins to brown. Return vegetables to saucepan and reduce heat to medium-low; mix well.
- Break up peeled plum tomatoes with hand and add tomatoes and juice to saucepan along with paprika, salt, black pepper, cayenne pepper, Worcestershire sauce, lemon juice and rosemary; mix well. Cover pan and simmer for 15 to 20 minutes.
- Stir the cornstarch into the yogurt and add to stew. Cook over low heat (do not boil), stirring occasionally, until sauce has thickened. Serve over rice, polenta or mashed potatoes.