Step 1

1 In a large pot or Dutch oven over medium heat, melt the butter

Step 2

2 Add the onions and salt, stir, cover and cook for 5 minutes

Step 3

3 Uncover and cook, stirring occasionally, until the onions are nicely browned in spots and the bottom of the pot is covered with stuck-on bits, 20 to 25 minutes

Step 4

4 Add the port to deglaze by scraping up any browned bits stuck to the bottom of the pot

Step 5

5 Add the stock or broth, pasta, thyme, and pepper, cover partially and increase the heat to bring to a boil

Step 6

6 Cook, stirring occasionally and adjusting the heat as needed to keep the mixture at a gentle, not rolling, boil, until the pasta is al dente and the liquid has reduced to coat the pasta, 15 to 20 minutes (see NOTE)

Step 7

7 Remove from the heat, discard the thyme, and stir in the cheese until melted

Step 8

8 Taste, and season with more salt and/or pepper, if needed

Step 9

9 Divide among bowls, sprinkle with more cheese and fresh thyme leaves, if desired, and serve

Step 10

10 NOTE: The pasta will continue to absorb liquid as it sits, so it’s okay if it is still saucy