Spaghetti With Cabbage, Pancetta, and Calabrian Chile

Ingredients
Method
Fill a large pot (at least 6 qt./L) with 1 gallon (4 L) of water; add 4 Tbsp. (40 g) kosher salt, cover the pot, and bring the water to a boil while you make your sauce. If the water begins to boil before your sauce is ready, turn down the heat, but don’t let the volume of the pasta water reduce by boiling off.
Heat a glug of extra-virgin olive oil in a large skillet over medium heat. When the oil is hot, add 2 oz. (60 g) pancetta, diced or cut into strips, and cook gently until it turns brown and crisp, 4–5 minutes. Take the pancetta out of the pan and set it aside, leaving the rendered fat in the pan.
Add ¾ Tbsp. unsalted butter to the pan and let it bubble and start to brown, then add 4 cups (8 oz./225 g) thinly sliced green, white, or savoy cabbage. Cook, stirring frequently, until the cabbage is tender and caramelizing a bit, about 10 minutes; you may need to increase the heat, but don’t let the bottom of the pan get too dark.
Add 1 tsp. thinly sliced oil-packed Calabrian chiles (from a jar; remove their seeds before slicing) and a splash of water from the pasta pot and simmer until the water has evaporated, another 1–2 minutes. Slide the skillet off the heat.
Bring the pasta water (back) to a boil, add 8 oz. (225 g) spaghetti, tagliatelle, or pappardelle, and set your timer for 2 minutes less than the shortest suggested cooking time on the package of pasta; this will ideally be 2 minutes before the pasta is al dente. Stir the noodles several times during the first 2 minutes of cooking to prevent them from sticking to the bottom of the pot or otherwise clumping together.
When the timer goes off, start tasting the noodles. When they seem like they are 1½–2 minutes away from a perfect al dente, drain and transfer them to the sauce in the skillet using your preferred method, making sure to reserve at least 1 cup (240 ml) of the pasta water.
Slide the skillet back onto medium heat and finish cooking the noodles, tossing and adding plenty of splashes of pasta water until the noodles are perfectly al dente, the cabbage is tender, and the sauce is nicely juicy. If the sauce seems watery, simmer for another few seconds to tighten it up, bearing in mind that the cheese will thicken it.
Reduce the heat to very low. Add the pancetta, ½ cup (60 g) 50/50 cheese (half Parmigiano-Reggiano, half Pecorino Romano, grated in a food processor), and remaining ¾ Tbsp. unsalted butter and toss to emulsify the cheese with the other sauce ingredients, adding splashes of pasta water (or plain hot water, if things are getting too salty) if needed to keep the consistency creamy and prevent the cheese from clumping. Taste and add more salt or Calabrian chiles if you like.
Divide the pasta between two warm bowls, tuck 2 lemon wedges into bowls, if using, and serve right away, with more cheese to add at the table.