Heat olive oil in a large skillet over medium-high heat. Sear the beef cubes on all sides until browned, then transfer to the slow cooker.
In the same skillet, sauté onions until soft. Add garlic, paprika, and caraway seeds, stirring until fragrant.
Stir in tomato paste, diced tomatoes, and beef broth. Bring to a light simmer, then pour the mixture over the beef in the slow cooker.
Cover and cook on low for 8 hours or high for 4-5 hours, until beef is tender.
One hour before serving, add sliced bell peppers and stir gently.
Serve hot over egg noodles, mashed potatoes, or crusty bread.