Step 1

Preheat the oven to 400°F (200°C).

Step 2

Make the mushroom sauce: Melt the butter in a medium pot over medium heat. Add the onion and sauté for 2–3 minutes, until the onion is translucent. Stir in the garlic and cook for 1 minute more, until fragrant. Add the Campbell’s® Cream of Mushroom Soup, vegetable stock, lemon juice, thyme, salt, and pepper and whisk until smooth. Bring to a simmer and cook, stirring occasionally, for 3–5 minutes, until the sauce has thickened slightly. Remove the pot from the heat.

Step 3

Make the stuffed shells: Heat the olive oil in a large, high-walled skillet over medium-high heat until simmering. Add the mushrooms and cook for 4–5 minutes, until softened and starting to brown. Stir in the kale and cook for another 3–4 minutes, or until reduced in volume and softened. Add the spinach and cook until wilted, 1–2 minutes. Turn off the heat and stir in the salt, 1 cup of the mushroom sauce, the ricotta, and ½ cup Parmesan until well combined. Season with more salt to taste.

Step 4

Spread half of the remaining mushroom sauce (about ½ cup) on the bottom of an 8-inch square baking dish.

Step 5

Stuff each pasta shell with 1½–2 tablespoons of the filling, then arrange in rows in the baking dish, filling-side up. Drizzle the remaining mushroom sauce on top, then sprinkle with the remaining ½ cup Parmesan cheese.

Step 6

Transfer the shells to the oven and bake for 10 minutes, or until the cheese is melted and the sauce is bubbling.

Step 7

Turn the broiler on high and broil the shells until the cheese is browned, 1–2 minutes. Remove from the oven and let rest for 2–3 minutes before serving.

Step 8

Enjoy!