Ingredients

4 pounds boneless short ribs, cut into 2-inch pieces

Coarse salt and freshly ground pepper

1/3 cup all-purpose flour

3 tablespoons safflower oil

1 medium yellow onion, halved and thinly sliced

5 garlic cloves, thinly sliced

2 bottles (12 ounces) stout, preferably Guinness (3 cups)

2 rosemary sprigs

1 pound cipollini onions, peeled

6 medium russet potatoes (3 1/2 pounds)

Extra-virgin olive oil, for brushing

Coarse salt and freshly ground pepper

Preparation

Make the filling: Preheat oven to 300 degrees. Season short ribs with salt and pepper. Dredge short ribs in flour, coating all sides. Transfer to a large plate. Heat oil in a large Dutch oven over high heat. Working in batches, brown short ribs, about 1 minute per side. Transfer to a large plate using kitchen tongs.

Reduce heat to medium. Add yellow onion to Dutch oven, and cook until golden, about 8 minutes. Add garlic. Cook for 2 minutes. Return meat to Dutch oven. Add stout and rosemary. Bring to a simmer. Cover, and transfer to oven. Bake for 2 1/2 hours.

Remove Dutch oven from oven, and add cipollini onions. Braise until meat is tender and onions are cooked through, about 30 minutes. Shred meat using 2 forks. Season with salt and pepper. Divide filling among eight mini (1-cup) pie plates, or transfer to a 12-inch (8-cup) gratin dish.

Make the topping: Raise oven temperature to 375 degrees. Peel potatoes, and very thinly slice each (preferably on a mandoline). Arrange potatoes over meat to form tight concentric circles, working around the edge and overlapping each potato by three-quarters. Brush with oil, and sprinkle with salt and pepper. Bake until topping is golden and filling is bubbling, about 45 minutes for mini potpies (1 hour for large potpie).