Heat large dutch oven over medium heat. Coat with oil and add beef. Saute until brown. Add onions and bell pepper and saute for 3 minutes. Add tomato, jalapenos, and garlic and stir well. Add wine and bring to a boil. Scrape all brown bits off bottom of pan. Stir in all other ingredients except squash, sour cream and cilantro. Mix well and bring to boil. Reduce to simmer and cover. Cook for 1 hour. Add squash and cilantro and cook covered for an additional hour. When ready to serve, place 1 tablespoon sour cream to top of each bowl.