Pat the beef cubes dry with paper towels and season generously with salt and black pepper.

Heat the vegetable oil in a large Dutch oven or heavy-bottomed pot over medium-high heat.

Brown the beef in batches until seared on all sides, then remove the meat and set aside.

Reduce the heat to medium. Add the chopped onions to the pot and cook for 5-7 minutes until softened and translucent.

Stir in the minced garlic, tomato paste, caraway seeds, and smoked paprika, cooking for 1 minute until fragrant (be careful not to burn the paprika).

Pour in the dark stout beer to deglaze the pot, scraping up any browned bits from the bottom with a wooden spoon.

Return the seared beef and any accumulated juices to the pot. Add the beef broth and bring the mixture to a simmer.

Cover the pot, reduce heat to low, and let it simmer gently for 1 hour.

Add the diced red bell pepper and continue to simmer uncovered for another 30-45 minutes, or until the beef is fork-tender and the sauce has thickened.

Taste and adjust seasoning with salt and pepper, then serve hot with a dollop of sour cream.