Hungarian Braised Beef with Paprika Pörkölt

Name: Hungarian Braised Beef with Paprika (Pörkölt)
Ingredients: 1⁄2 cup rendered pork lard or vegetable oil; 12 oz. oxtail, cut into 1-inch-rounds (have your butcher do this); 2 1⁄2 lb. beef shoulder, cut into 1-inch cubes; 2 large yellow onions, roughly chopped; 4 cloves garlic, thinly sliced; 2 cups red wine; 1⁄4 cup Hungarian sweet paprika; 4 Hungarian wax peppers, stemmed, seeded, and thinly sliced crosswise; 2 vine-ripe tomatoes, cored and cut into 1/2-inch wedges; Kosher salt and freshly ground black pepper; Sour cream and gherkins, for serving