Method

• Prepare the vegetables: Slice the onions, mince the garlic, dice the tomatoes, and slice the bell peppers. Trim the fat from the meat and cut the beef into 3 cm cubes.
• Heat the butter and olive oil in a thick-bottomed pot. Sear the meat over high heat in batches, adding more butter and oil as needed. Cook each batch for 5-6 minutes until browned on all sides. Transfer the meat to a plate.
• After cooking the meat, reduce the heat to low and cook the onions for about 15 minutes, stirring occasionally, until soft. Return the meat to the pot, add paprika and cumin, and cook for 1 minute, stirring.
• Add the minced garlic, diced tomatoes, and sliced bell peppers, then pour in the broth. Season with salt and pepper. Mix well.
• Cover and cook on very low heat, stirring occasionally, until the meat is tender and sauce thickens, about 1.5 hours, adding more broth if necessary to keep moist.
• Peel and dice the potatoes and add them to the pot. Continue cooking for 30 minutes, until the potatoes are tender. Check the seasoning.
• Top with a small spoonful of sour cream (optional) and serve.