French Onion Stuffed Shells

• servings: 6 servings
• active time: 50 minutes
• total time: 1 hour 30 minutes

Ingredients

5 tbsp. salted butter, plus more for the baking dish

2 lb. onions, thinly sliced

1 1/2 tsp. kosher salt, plus more for the pasta water

3/4 tsp. black pepper

1 lb. cremini mushrooms, sliced

1/2 c. dry white wine

2 tsp. chopped fresh thyme

2 garlic cloves, finely chopped

24 jumbo pasta shells (about 8 ounces)

1 (15-ounce) container whole-milk ricotta cheese

1 large egg

2 c. shredded gruyère cheese (about 8 ounces)

3/4 c. grated parmesan cheese (about 3 ounces)

1 c. beef broth

1 c. heavy cream

1 tbsp. balsamic vinegar

1/2 c. panko

2 tbsp. chopped fresh chives

Directions

Preheat the oven to 400˚F. Butter a 9-by-13-inch baking dish. Heat 4 tablespoons of the butter in a medium skillet over medium-low heat. Add the onions and season with ½ teaspoon salt and ¼ teaspoon pepper; stir. Cover and cook, stirring once, until the onions are softened and translucent, about 10 minutes. Uncover, increase the heat to medium, add the mushrooms and cook, stirring occasionally, until very soft and deeply golden, 15 more minutes.

Add the wine, thyme, and garlic to the pan and cook, stirring, until the liquid evaporates and the onions are caramelized, about 5 more minutes. Remove half of the onions and mushrooms to a cutting board to cool slightly. Finely chop.

Meanwhile, bring a large pot of salted water to a boil. Add the pasta shells and cook 1 minute less than the package directs. Drain and add to the prepared baking dish.

Stir together the ricotta, egg, chopped onions and mushrooms, 1 cup of the gruyère, ½ cup of the parmesan, ½ teaspoon salt, and ¼ teaspoon pepper in a medium bowl. Spoon the filling into the shells and arrange open-side up in the pan.

Add the beef broth and heavy cream to the remaining vegetables in the skillet and bring to a boil over medium heat. Season with the remaining ½ teaspoon salt and ¼ teaspoon pepper and cook, stirring, until thick enough to coat the back of a spoon, about 5 minutes. Remove from the heat and whisk in the balsamic vinegar and remaining 1 cup gruyère. Spoon the sauce over the stuffed shells.

Microwave the remaining 1 tablespoon butter in a medium bowl until melted. Stir in the panko and remaining ¼ cup parmesan. Sprinkle the shells with the panko mixture and bake until the panko is golden brown and the sauce is bubbling, 25 to 30 minutes. Let cool about 10 minutes. Sprinkle with the chives before serving.

Nutrition

• Calories: 920
• Total Fat: 49 g
• Saturated Fat: 30 g
• Trans Fat: 1 g
• Cholesterol: 187 mg
• Sodium: 1187 mg
• Total Carbohydrate: 75 g
• Dietary Fiber: 6 g
• Total Sugars: 12 g
• Protein: 38 g