• Adjust rack to top position and preheat oven to 450 degrees. Bring a large pot of salted water to a boil. Wash and dry produce. • Trim and thinly slice mushrooms (skip if your mushrooms are pre-sliced!). Halve, peel, and thinly slice onion. Trim and thinly slice scallions, separating whites from greens. • In a small bowl, combine panko, half the Parmesan, a drizzle of olive oil (large drizzle for 4 servings), salt, and pepper. Set aside.

• Heat a drizzle of oil in a large pan over medium-high heat. Add mushrooms; cook, stirring occasionally, until browned and slightly crispy, 5-7 minutes. Season with salt and pepper. • Turn off heat; transfer to a plate. Wash out pan and set aside to cool slightly.

• Once water is boiling, add cavatappi to pot. Cook, stirring occasionally, until al dente, 9-11 minutes. • Reserve 1⁄2 cup pasta cooking water(1 cup for 4 servings), then drain.

• Heat a large drizzle of oil in pan used for mushrooms over medium-low heat. Add onion and scallion whites; cook, stirring occasionally, until browned and softened, 8-10 minutes. • Reduce heat to low. Add 1 tsp sugar(2 tsp for 4 servings) and a splash of water. Cook, adding additional splashes of water as necessary, until onion is caramelized and jammy, 1-2 minutes more. Season with salt and pepper.

• To pan with onion mixture, add mushrooms, cream sauce base, and stock concentrate. Cook, stirring, until simmering, 1-2 minutes. • Stir in cream cheese, cheddar, remaining Parmesan, and 2 TBSP butter (4 TBSP for 4 servings) until melted and combined. TIP: If sauce seems too thick, stir in reserved pasta cooking water a splash at a time until sauce reaches desired consistency. If pasta isn’t finished cooking, ladle pasta water directly from pot. • Season with pepper to taste.

• Stir drained cavatappi into pan with sauce. • Transfer pasta and sauce to an 8-by-8-inch baking dish (9-by-13-inch baking dish for 4 servings). Evenly sprinkle with panko mixture. Bake on top rack until panko is golden brown, 2-4 minutes.

• Garnish pasta bake with scallion greens. Serve directly from baking dish.