Pasta with Creamy Mushroom Ragu

 3 Tbsp. extra-virgin olive oil

1small onion, finely chopped

Kosher salt

6 garlic cloves, thinly sliced

¼ cup double-concentrated tomato paste

12 oz. mixed mushrooms (such as cremini, shiitake, oyster, and/or maitake), tough stems trimmed, coarsely chopped

¼ cup heavy cream

Freshly ground black pepper

12 oz. rigatoni or other short pasta

2 Tbsp. unsalted butter

1oz. Parmesan, finely grated (about ½ cup), plus more for serving

Heat oil in a small pot or large saucepan over medium. Add onion and a big pinch of salt. Cook, stirring occasionally, until onion is very soft, 6–8 minutes. Add garlic and cook, stirring often, until softened and beginning to turn golden around edges, about 4 minutes.

Add tomato paste to pot and cook, stirring constantly, until slightly darkened in color, about 1 minute. Add mushrooms and season with more salt. Cook, stirring often, until softened, 6–8 minutes.

Add cream and 1 cup water, increase heat to high, and bring to a boil. Reduce heat and simmer, stirring occasionally, until ragù is slightly thickened, 13–17 minutes. Taste and season with pepper and more salt as needed.

Cook pasta in a large pot of boiling salted water, stirring occasionally, until very al dente, about 2 minutes less than package directions. Drain, reserving 2 cups pasta cooking liquid.

Add pasta, butter, 1 cup pasta cooking liquid, and 1 oz. Parmesan to ragù. Cook, tossing and adding more pasta cooking liquid by ¼-cupful as needed, until sauce coats pasta and pasta is al dente, about 2 minutes.

Divide pasta among shallow bowls or plates and top with more Parmesan.