Pasta with Sausage and Mushrooms

Dark and moody in colour but surprisingly bright and light to eat, this quick dish comes together in just 30 minutes. Hot Italian sausage sings backup in this dish to a lb of mushrooms and a heap of caramelized red onion. A glug of balsamic vinegar, used to scrape up any browned bits that build up on the bottom of the pot, adds complexity, acidity and a little sweetness in one fell swoop. Use a mid-length tube-shaped pasta so all the mushroom and sausage bits have a place to hide.

12 oz medium tube pasta, such as mezzi rigatoni or pipe rigate
1½ tsp. sea salt, divided
4 Tbsp. extra-virgin olive oil, divided
4 Tbsp. butter, divided
1 lb crimini or button mushrooms, cut into ¼" pieces
8 oz hot Italian sausage
1 large red onion, finely chopped
4 cloves garlic, coarsely chopped
2 Tbsp. tomato paste
¼ tsp. crushed red pepper flakes
black pepper, freshly ground
⅓ cup balsamic vinegar

To Serve:
finely grated Parmesan cheese

Cook 12 oz medium tube pasta in a large pot of boiling salted water, stirring occasionally, until al dente. Drain, reserving 1 cup pasta cooking liquid.

Meanwhile, heat 2 Tbsp. extra-virgin olive oil and 2 Tbsp. butter in a large Dutch oven or other heavy pot or skillet over medium-high until butter is melted. Add 1 lb crimini or button mushrooms, cut into ¼" pieces and cook, stirring occasionally, until slightly softened, about 2 minutes. Add 1 tsp. sea salt; cook, stirring occasionally, until liquid is evaporated and mushrooms are browned, 5-7 minutes. Transfer to a small bowl.

Heat remaining 2 Tbsp. extra-virgin oil in same pot over medium-high. Add 8 oz hot Italian sausage and ½ tsp. sea salt. Cook, breaking meat into smaller pieces with a wooden spoon or heatproof rubber spatula, until cooked through, about 2 minutes.

Add 1 large red onion, finely chopped and cook, stirring occasionally, until lightly browned, about 5 minutes. Add 4 cloves garlic, coarsely chopped and cook, stirring often, until combined and fragrant, about 2 minutes. Return mushrooms to pot and add 2 Tbsp. tomato paste and ¼ tsp. crushed red pepper flakes; season with black pepper, freshly ground. Cook, stirring often, until paste is darkened in colour, about 2 minutes. Pour in ⅓ cup balsamic vinegar and cook, scraping up any browned bits stuck to bottom of pot, 30 seconds.

Reduce heat to medium. Add pasta, ½ cup reserved pasta cooking liquid and remaining 2 Tbsp. butter. Cook, stirring often and adding more pasta cooking liquid a little at a time if needed, until pasta is coated and sauce is glossy, about 30 seconds.

Transfer pasta to a platter; top with finely grated Parmesan cheese.

Makes 4 servings.