Halve the peppers lengthwise and rub them all over with little more of the olive oil. Grill, skin-side up, until black and charred. Transfer to a bowl and cover with plastic wrap. When cool enough to handle, peel off the skin and slice away the seeds and pith. Either finely chop or place in a food processor and blitz until it forms a rough puree.
Place the diced beef into a large mixing bowl with the spices, salt and pepper and toss well so it is evenly coated.
Heat half the olive oil in a heavy based saucepan or casserole dish over a medium heat. When the oil is sizzling, brown the beef in batches, so that the heat stays high. Add the onion, garlic and sprinkle over a little more paprika, cayenne pepper, caraway seeds. Add the thyme, chilli, and the bay leaf. Lower the heat and saute gently for 5 minutes, or until the onion starts to soften.
Add the wine, sherry vinegar, stock, passata and tomatoes. Stir in the roasted peppers and potatoes. Season to taste with salt and pepper and lower the heat. Simmer uncovered, gently to up to an hour or until meat is tender. Top up with extra stock or water if needed.
Just before serving stir through parsley. Ladle into bowls and top with a dollop of sour cream, a sprinkle of paprika and chopped chives. Serve with warm crusty bread.