Heat olive oil in a large skillet over medium high heat. Add ground beef and cook until browned, about 3-5 minutes, making sure to crumble the beef as it cooks; drain excess fat. Add garlic, onion and chili. Cook, stirring occasionally, until tender, about 4-6 minutes. Place ground beef mixture into a 6-qt slow cooker. Stir in beef stock, kidney beans, black beans, crushed tomatoes, diced tomatoes, chili powder, paprika, oregano, cumin and hot sauce; season with salt and pepper, to taste. Cover and cook on low heat for 7-8 hours or high heat for 5-6 hours. Serve immediately, garnished with sour cream, green onions and corn chips, if desired.