Directions

1. Heat the oven to 400°F.
2. Bring a large pot of abundantly salted water to a boil over high heat.
3. Meanwhile, strip the kale leaves from their stems (saving the stems for another use). Blanch the leaves until bright green and tender, 5 to 7 minutes. Using tongs, transfer the cooked kale leaves to a colander and run under cold water until the leaves are cool enough to handle. Squeeze all the water out of the kale, finely chop, and place in a medium bowl. Reduce the heat under the water to medium-low, cover the pot, and keep the water at a simmer (for cooking the pasta and peas later on).
4. To prepare the sauce: Melt the butter in a large, high-rimmed skillet or pot over medium heat. Reduce the heat to medium-low, add the garlic and red pepper flakes, and cook until the garlic is fragrant and just starting to turn light golden, 2 to 3 minutes. Increase the heat back to medium, add the flour and cook, whisking frequently, until the roux is barely light beige, 3 to 4 minutes. Whisk in the milk in a slow, steady stream, until the milk and roux are incorporated and the mixture is smooth. Bring to a simmer and cook, whisking occasionally, until it thickens enough to cling to the back of the spoon, 5 to 7 minutes.
5. Reduce the heat to low, then add the cream cheese and whisk until it dissolves into the sauce. Add the Gruyère, Parmigiano-Reggiano, salt, pepper, and nutmeg and stir to combine (it’s okay if the grated cheese isn’t fully melted). Taste and adjust the seasoning if necessary. Turn off the heat, cover, and keep warm while you cook the pasta.
6. While the sauce is cooking, increase the heat under the pot of kale-cooking water to high and bring back to a boil. Add the pasta and cook until almost al dente, about two-thirds of the time on the package’s directions. During the last minute of cooking, add the frozen peas. Drain the pasta and peas and return it to the pot along with the turkey and reserved chopped kale.
7. To assemble, add the cheese sauce to the pasta, peas, and turkey. Stir to combine. Transfer the mixture to a 9x13-inch baking dish.
8. For the panko topping, mix all the ingredients in a medium bowl, making sure all the bread crumbs are coated in the melted butter. Evenly sprinkle on top of the pasta.
9. Place the baking dish on a baking sheet (to catch any sauce that bubbles over). Bake until the casserole is fully heated through and the bread crumbs are deep golden brown and crispy, 22 to 25 minutes. Allow to cool for at least 5 minutes before serving and enjoy hot or warm.