Put the flour in a large mixing bowl and season. Toss a third of the beef in flour to coat, shaking off excess. Heat 1tbsp oil in a large frying pan over medium heat. Fry meat until browned all over. Remove with a slotted spoon to the slow cooker after each batch. Repeat with the remaining meat using 1tbsp oil each time. Add the stock to the pan, scraping up brown bits.
Pour the stock into the slow cooker slowly and mix well with the beef. Mix in the onions, ale, bay leaf and thyme. Finally stir in the mushrooms and carrots and season. Cover with a lid and cook on high for 4hr.
Meanwhile, make dumplings. Mix all ingredients, apart from cheese, in a bowl with plenty of seasoning, or pulse in a food processor until mixture resembles breadcrumbs. Add cheese and mix in to form larger flakes, then sprinkle over 1–2tbsp water to bring the dough together. Roll into 6 balls and dot around stew leaving a 2cm gap between them. Cover again with the lid and cook for a further 1hr.
