Kosher salt and black pepper
tablespoons unsalted butter
tablespoons extra-virgin olive oil
large yellow onion, roughly chopped into 1/4-inch pieces
medium carrots, roughly chopped into 1/4-inch pieces
medium (1 to 1 1/2-pound) cauliflower, stem and head coarsely chopped into pieces no bigger than 1/2 inch
cup tomato paste
tablespoons low-sodium soy sauce
garlic cloves, coarsely chopped
cup whole milk
fresh bay leaf or thyme sprig
pound rigatoni or another ridged dried pasta, or fresh pappardelle or tagliatelle
cup finely grated Parmesan, plus more for serving
- Bring a large pot of salted water to a boil. Meanwhile, in a large Dutch oven, melt 2 tablespoons butter with the olive oil over medium-high. When foaming, add the onion, carrots and cauliflower, season with 1 teaspoon salt and a few pepper grinds. Cook, stirring just once or twice, until browned and juicy, 5 to 7 minutes. Add the tomato paste, soy sauce and garlic and cook, stirring and smashing the vegetables, until the tomato paste is a shade darker and sticks to the bottom of the pot, 2 to 3 minutes.
- Add the milk and bay leaf, season with salt and pepper, reduce heat to low, and stir to combine, scraping up browned bits from the pot. Cover and cook, stirring occasionally, until the milk has thickened slightly and the vegetables are very soft, 15 to 20 minutes. (At first the pan will look dry, then the vegetable liquid will thin the sauce and it will thicken slightly).
- Halfway through cooking the sauce, add the pasta to the boiling water and cook until al dente. Reserve 1 cup pasta water and drain. If the sauce is ready before the pasta, remove sauce from heat and keep covered.
- Remove the bay leaf from the sauce. Season to taste with salt and pepper. Increase heat to medium-high. Add the pasta, 1/2 cup pasta water, the Parmesan and the remaining 1 tablespoon butter. Stir vigorously until the pasta is well coated, adding more pasta water as needed until the sauce is glossy. Season to taste with salt and pepper, and serve with more grated Parmesan on top.