Kosher salt and freshly ground black pepper, to taste
⅓ cup all-purpose flour
2 garlic cloves, minced
1 medium yellow onion, thinly sliced
1 medium carrot, small dice
4 ounces button mushrooms, quartered
2½ cups red wine (preferably a Burgundy Pinot Noir), divided
2 teaspoons chopped fresh rosemary
1 teaspoon chopped fresh thyme
2 pounds (6 medium) Yukon Gold potatoes, peeled and cut into 2-inch pieces
½ cup grated Parmesan
1 teaspoon chopped fresh rosemary
5 garlic cloves, finely minced
1½ sticks unsalted butter, softened
Directions
Make the braised short ribs: In a 6-quart dutch oven, melt the butter over medium high heat. Cook until it begins to brown, 2 minutes, then add the short ribs and season with salt and pepper. Cook, stirring as needed, until golden brown, 6 to 8 minutes. Using a slotted spoon, transfer the short ribs to a bowl and toss with the flour to coat.
Add the garlic, onions and carrots to the pot, and sweat until they soften, 3 to 5 minutes. Add the mushrooms and cook another 2 minutes. Pour in ½ cup of red wine, scraping the bottom to deglaze the pan. Cook until the liquid has evaporated and the vegetables begin to caramelize, 8 to 10 minutes.
Add the reserved short ribs, the remaining wine, the rosemary and thyme to the pot and bring to a simmer. Reduce the heat to low and cook, covered, until tender 45 to 55 minutes. Preheat the oven to 375º.
Meanwhile, make the whipped potatoes: Bring a pot of salted water to a boil. Cook the potatoes until tender, 10 to 12 minutes. Drain the potatoes well and transfer to the bowl of a stand mixer fitted with the paddle attachment. Whip the potatoes until smooth and no longer steaming, 5 to 7 minutes, then add the remaining ingredients and mix until incorporated.
Spread the braised short ribs evenly in a 9-inch pie dish. Top with the whipped potatoes and place the dish on a baking sheet. Bake until the potatoes begin to caramelize, 20 to 25 minutes. Let cool slightly, then serve.