In a large ovenproof skillet, warm the oil over medium heat. Add the onion and garlic and cook for 2 to 3 minutes, or until soft but not browned. Add the beef and cook for 3 to 5 minutes, or until browned on all sides. Add the carrots and celery and stir to coat. Stir in the ale, stock, tomato paste, Worcestershire sauce and thyme. Bring to a boil, then reduce heat to low, cover, and simmer for 30 minutes.
Uncover and cook 15 to 20 minutes longer, or until the meat and vegetables are tender and the sauce starts to thicken. Remove from the heat.
To make the cobbler: Preheat the oven to 350 degrees. Sift the flour and mustard into a food processor. Season with salt and pepper. Add the butter, and pulse 4 to 5 times, or until the mixture resembles coarse crumbs. Add the cheese, hot sauce and ½ cup water. Process for 8 to 10 seconds, or until a soft dough forms. Add more water, if necessary.
Transfer the dough to a floured surface. Roll it out to ½-inch thickness. With a 3-inch round cookie cutter, cut out 7 to 8 rounds; reroll and cut out more rounds to make 12. Arrange on top of the meat mixture, overlapping in a decorative pattern. Brush the tops of the cobbler with the milk.
Bake for 30 to 35 minutes, or until the cobbler is golden and the mixture is bubbling. Remove from the oven and serve immediately.
Nutrition information per serving: