Heat oil in large stockpot. Saute onions and garlic for 2 to 3 minutes or until onion is tender. Remove from pan and set aside. Brown beef and chicken sausage, breaking up into very small pieces. When browned, drain fat from meat. Place meat back in pan and slowly add all remaining ingredients and spices (including onion mixture and strawberry puree) to the meat. Bring to a boil, then decrease heat. Simmer for 2 hours. Alternatively, you can saute onion, brown the meat, add to slow cooker with remaining ingredients and cook on low for 4 hours.