Kielbasa and cheese is an incredibly comforting combination. And the torn kale in this recipe holds onto the cheese sauce so well it becomes almost tastier than the macaroni itself. We used sharp Cheddar for this recipe, but 1 pound of your favorite melting cheese will work as well. Just don't use a cheese aged longer than 12 months or your sauce might get grainy or separate.
Bring a large pot of water to a boil. Salt the water and add the macaroni. Cook, stirring occasionally, until al dente, about 9 minutes. Drain.
Meanwhile, heat 1 tablespoon oil in a large heavy pot over medium-high heat until very hot, about 1 minute. Add the kale and 1/4 cup water, cover and let cook until wilted and just tender, about 2 minutes. Uncover, toss the kale, and continue cooking until all of the water has evaporated, 4 to 5 minutes. Transfer the kale to a medium bowl and set aside.
Heat the remaining 1 tablespoon oil in same pot over medium-high heat. Add the onion and garlic and cook until the onion is tender and begins to brown, 4 to 5 minutes. Add the kielbasa and cook, tossing occasionally, until lightly browned, 2 to 3 minutes. Add the flour, stir to coat and cook for 1 minute. Stir in the milk and kale and bring to a boil; add the cheese a few handfuls at a time and stir to combine. Reduce the heat to low and cook, stirring frequently, until the cheese has completely melted, about 2 minutes.
Stir the macaroni into the cheese mixture until evenly coated; remove from the heat. The sauce will look very loose but will thicken off the heat.
Feel free to stir in a second pinch of cayenne pepper if desired.