Remember that Seinfeld episode where Elaine started selling muffin tops? That's where this cast iron skillet meatloaf came from -- more crusty, ketchup-ey meatloaf top to go around. The recipe calls for rhubarb ketchup but you can substitute regular tomato ketchup -- it won't have as much of a 'bite' but will still get that nice crusty top (and that's what I was going for)!
Meatloaf with Mushrooms, Red Wine, and Rhubarb Ketchup
2 pounds ground beef
1 medium onion, chopped
8 ounces of cremini mushrooms, chopped (can substitute white button mushrooms)
3 medium garlic cloves, minced
2 large eggs, beaten
1 cup red wine
1/2 cup Asiago cheese, shredded
1/2 cup breadcrumbs
1 cup rhubarb ketchup (recipe here), plus more for serving
3 tablespoons butter, divided
1 1/2 tablespoons Worcestershire sauce
1 teaspoon fresh thyme, chopped
1 teaspoon fresh rosemary, chopped
1 teaspoon kosher salt
1 teaspoon black pepper
Heat the oven to 350 degrees and using 1 tablespoon of butter, grease the cast iron skillet and set aside.
Melt the remaining two tablespoons of butter in a large sauté pan over medium heat and add the onions, mushrooms, thyme, rosemary, and salt. Cook, stirring occasionally, until the onions are softened and any moisture from the mushrooms has evaporated, about 10 minutes. Add the garlic and cook for another minute, or until the garlic is fragrant.
Add the wine to the pan and simmer until the wine has almost completely evaporated, about 5 minutes. Place the vegetables in a large bowl, set aside and let cool for 10 minutes.
While the vegetables are cooling, place the beaten eggs in bowl and add the Worcestershire sauce and black pepper and set aside.
Add the eggs, ground beef, 1/2 cup of rhubarb ketchup, breadcrumbs, and cheese to the cooled vegetable mixture in the bowl and, using your hands, combine thoroughly. Place the meatloaf mixture in the buttered cast iron skillet, brush with remaining 1/2 cup of rhubarb ketchup, and place in oven. Bake meatloaf until an instant-read thermometer inserted into the center registers 155°F, 60–75 minutes. Let rest 15 minutes before slicing. Serve with more rhubarb ketchup alongside.