Season beef with salt and pepper and transfer to slow cooker
In a food processor or blender, puree red peppers, paste and vinegar until well blended, about 2 minutes.
In a dutch oven over medium heat, heat oil and add carrots, onion and 1 teaspoon salt. Cover and cook until onions are soft, about 8 minutes.
Stir in flour, remaining salt and pepper, bayleaf and red pepper mixture. Cook until mixture starts to brown, about 2 minutes. Stir in wine and scrape up any browned bits. Transfer mixture to slow cooker and stir until beef is coated.
Cover and cook until meat is tender, about 7 hours on low. Turn off slow cooker and let stew rest for 5 minutes. Skim off any fat and discard bay leaf.
Transfer 1/3 cup of hot stew to small bowl. Combine with sour cream and return to stew.
Add additional salt and pepper to taste, and sprinkle with parsley.