In this rustic beef stew, tomatoes and a small amount of vinegar brighten the flavors of the dish.
Place a deep skillet or casserole that can be covered over medium-high heat, and add oil. Brown meat well on all sides, seasoning with salt and pepper, for 10 minutes; remove with a slotted spoon.
In same pot over medium-high heat, sauté onion and tomatoes with a large pinch of salt and some pepper. When they soften, about 5 minutes, stir in paprika, cinnamon, and bay leaf. Return meat to pan, and add stock and wine; bring to a boil, then lower heat, cover, and simmer for 30 minutes. If mixture starts to dry, add a little water or stock.
Remove cinnamon and bay leaf, and stir in sugar and prunes. Simmer until prunes and meat are soft, another 30 to 45 minutes. (Dish can be made in advance to this point; let sit for a few hours, or cover and refrigerate for up to a day before reheating and proceeding.) When meat is very tender, uncover pot and add vinegar; if necessary, raise heat so sauce thickens and becomes glossy. Season to taste with salt and pepper, and serve hot, garnished with parsley.