Beef roll with cheese in a slow cooker

Ingredients:

• 340 g tomato paste
• 800 g whole canned San Marzano tomatoes, crushed by hand
• 0.5 tsp red pepper flakes
• 0.5 tsp sugar
• 1 small bunch basil, leaves picked (about 10 leaves)
• 1 piece (0.7-0.8 kg) of beef flank
• 1 and 2/3 cups (170 - 200 g) grated provolone cheese
• 3 small cloves garlic, finely chopped
• 1 tbsp. panko breadcrumbs
• 0.5 tbsp. (about 55 g) grated Pecorino Romano cheese
• 1/3 cup golden raisins
• 1/4 cup pine nuts or chopped walnuts
• 1 cup fresh parsley
• Polenta, for filing

Preparation:

1. In a 5.5-quart slow cooker, combine 2 cups of hot water with the tomato paste. Add the canned tomatoes, red pepper flakes, sugar, and basil, and stir to combine. Close the lid and cook on high while you prepare the meat.
2. Butterfly steak: Slice the beef horizontally, leaving one long edge intact, so the steak can be opened like a book, resembling the wings of a butterfly. Place the meat between two sheets of plastic wrap and pound to a thickness of 6 mm. Remove the wrap; season the meat with salt and pepper. Sprinkle the beef evenly with provolone cheese, scatter garlic on top, and sprinkle with breadcrumbs, pecorino cheese, raisins, pine nuts, and parsley.
3. Roll the meat tightly along the short edge. Tie in several places with twine. Transfer to a slow cooker; set the cooker to low, close the lid, and cook for 7 hours.
4. Place the meat on a cutting board and let it rest for 5 minutes. Remove the twine and slice into 2.5 cm thick slices. Serve the beef roulade with polenta; drizzle generously with the slow cooker sauce.