Put a big pot of water on to boil, and salt water liberally. When water is boiling, cook the pasta according to directions. Drain, but reserve some pasta cooking water in case the dish is too dry at the end.
While waiting for the water the boil and the pasta to cook, prep and cook the rest of the dish. Wash the kale, rinsing under cold running water. Remove tough stems and tear or cut the kale into chunks about half the size of your palm.
Heat 1-2 tablespoons of olive oil in a very large skillet or Dutch oven over medium-high heat. Add the garlic and cook until fragrant, about 30 seconds. Add the sausage and break it apart into bite-size pieces with chopsticks or a wooden spatula. Add crushed red pepper flakes and continue cooking until sausage is browned and mostly cooked through, with just a tiny hint of pink in the middle. This will take 5-7 minutes.
Add the kale into the skillet and season with a few dashes of salt and generous black pepper. Cook, stirring, until the kale wilts, about 5 minutes. If you have way too much kale for your pan, as I always do, don’t fret. Just pile in as much as you can, and continue stirring and rotating. When the kale in the pan starts to cook down, add the rest of the kale and continue stirring to distribute.
When the kale is wilted and soft, and the sausage is completely cooked through, add the cooked and drained pasta, stirring in some pasta water if the dish looks too dry. Toss everything together, cooking for about another minute or two.
Optional Add-Ins:
Protein:
Pancetta - Cook together with the sausage, or substitute pancetta for sausage. Pancetta is fattier and saltier than sausage, so I usually use about 8 ounces of pancetta if I’m substituting entirely.
Chicken - This dish really works best with sausage, because that’s what provides most of the fat and flavor. However, I have made it with chicken before. In this case, dice up 1 pound of chicken breast or chicken thighs, and cook in place of the sausage. While cooking, season liberally with salt, pepper, and whatever spices you have in your cabinet. I like using cumin, chili powder, coriander, onion powder, and white pepper. Add some generous splashes of these spices while you’re cooking the chicken, and be liberal with the olive oil!
Vegetables:
Onion - I almost always add an onion now, although when I started this recipe I never used to. I think it adds a depth of flavor and is an incredibly easy step. Chop one onion and add it to the olive oil with the garlic. Cook until the onion starts becoming translucent, about 3, then add the sausage meat.
Mushrooms - You can see in the pictures we've added mushrooms here. I use about 8 ounces of sliced mushrooms (use your favorite variety; this dish can also accommodate more if you really like mushrooms). Add the mushrooms to the cooking sausage after the sausage is just starting to brown, after about 3 minutes.
Spinach - Add a few handfuls of spinach along with the kale. Alternatively, you can substitute spinach for kale.
Aromatics:
Garlic powder, chili powder, white pepper - Add them to the cooking meat, the cooking kale, or the final product!
Herbs: parsley, oregano - Add at the end when you’re tossing the dish together.
Sauces - Stir in some tomato sauce or fresh cream when tossing all the ingredients together.