Ingredients

For the meatloaf:

• Cooking spray
• 1 small yellow onion (about 6 ounces)
• 1 small carrot (about 2 ounces)
• 1 medium stalk celery
• 4 cloves garlic
• 1 tablespoon unsalted butter
• 2 tablespoons gochujang (Korean red pepper paste)
• 1 tablespoon soy sauce
• 1 teaspoon Worcestershire sauce
• 4 ounces fresh shiitake mushrooms
• 1/4 medium bunch fresh parsley
• 1/4 cup grated Parmesan cheese
• 2 cups panko breadcrumbs
• 1 pound ground pork
• 1 pound ground beef
• 2 large eggs
• 1/4 cup heavy cream
• 1 teaspoon kosher salt
• 1/4 teaspoon freshly ground black pepper

For the gochujang glaze:

• 1/2 cup gochujang (Korean red pepper paste)
• 1/4 cup packed light or dark brown sugar
• 2 teaspoons toasted sesame oil

1. Arrange a rack in the middle of the oven and heat the oven to 350ºF. Line a rimmed baking sheet with aluminum foil and coat with cooking spray.
2. Prepare the following, adding each to a food processor fitted with the blade attachment as you complete it: Peel 1 small yellow onion and 1 small carrot, then coarsely chop. Coarsely chop 1 medium celery stalk. Add 4 peeled garlic cloves. Pulse until finely chopped, about 15 (1-second) pulses.
3. Melt 1 tablespoon unsalted butter in a medium frying pan over medium heat. Add the vegetable mixture and cook, stirring frequently, until softened and most of the moisture has evaporated, about 5 minutes. Turn off the heat.
4. Add 2 tablespoons gochujang, 1 tablespoon soy sauce, and 1 teaspoon Worcestershire sauce, and stir until combined. Transfer to a large bowl and refrigerate until cooled to the touch, about 20 minutes.
5. Meanwhile, remove the stems from 4 ounces fresh shiitake mushrooms. Place in the food processor (no need to clean) and pulse until finely chopped, about 10 (1-second) pulses. Pick the leaves from 1/4 medium bunch fresh parsley and finely chop until you have 1/4 cup. Finely grate Parmesan cheese until you have 1/4 cup if needed, or measure out 1/4 cup store-bought.
6. When the vegetable mixture is ready, add the mushrooms, parsley, Parmesan, 2 cups panko breadcrumbs, 1 pound ground pork, 1 pound ground beef, 2 large eggs, 1/4 cup heavy cream, 1 teaspoon kosher salt, and 1/4 teaspoon black pepper. Gently mix with your hands until evenly combined.
7. Transfer the meatloaf mixture to the baking sheet and shape it into a 9 by 5-inch loaf. Alternatively, line a 9x5-inch loaf pan with plastic wrap and pack it with the meatloaf mixture; invert onto the baking sheet, then remove the plastic wrap and loaf pan.
8. Bake for 30 minutes. Rotate the baking sheet 90 degrees. Bake until an instant-read thermometer inserted in the center registers at least 150ºF, about 30 minutes more (it will continue to rise in temperature as it rests).
9. Remove the meatloaf from the oven and let it rest for 10 minutes. Meanwhile, increase the oven temperature to 500ºF. Make the glaze: Place 1/2 cup gochujang, 1/4 cup packed brown sugar, and 2 teaspoons toasted sesame oil in a small saucepan. Cook over medium heat, stirring occasionally, until the sugar is dissolved and the glaze is bubbling. Remove the pan from the heat.
10. Brush about half the glaze over the top and sides of the meatloaf. Return to the oven and bake until the glaze bubbles, 1 to 2 minutes. Slice with a serrated knife and serve with the remaining glaze.