Cook the pasta in a large pot of well-salted water according to package directions until al dente. Before draining, reserve ¼ cup (600 ml) pasta cooking water, then drain the pasta and set aside.
16 oz (454 g) dry casarecce pasta
Heat the olive oil in a large skillet over medium heat. Add the mushrooms and cook for about 6 minutes, stirring occasionally, until they have released their moisture and browned. Add the shallot, garlic and ginger and cook for about 2 minutes, stirring frequently, until the shallot has softened and the garlic is fragrant.
3 tbsps (45 ml) olive oil, 10 oz (283 g) white button mushrooms, ¼ cup (40 g) finely chopped shallot, 2 tbsps (18 g) minced garlic, 1 tsp (5 g) fresh ginger, crushed into a paste
Stir in the gochujang, gochugaru, if using, soy sauce, toasted sesame oil and brown sugar. Cook for 1 to 2 minutes, stirring frequently so the mixture cooks against the surface of the pan without scorching.
2-3 tbsps (32 - 48 g) Gochujang (Korean chili paste), 1 tsp (2 g) Gochugaru (Korean pepper flakes), 2 tsps (10 ml) low sodium soy sauce, 1½ tsps (7.5 ml) toasted sesame oil, 1 tsp (4 g) light brown sugar
Pour in the heavy cream and stir until the gochujang mixture is fully incorporated. Bring to a low simmer and cook for about 10 minutes, stirring occasionally, until the sauce has reduced and thickened slightly.
1¼ cups (300 ml) heavy cream
Add the drained pasta, butter and only ¼ cup (60 ml) of the reserved pasta water to the skillet, to start. Toss over low heat until the butter has melted and the pasta is evenly coated, adding additional pasta water only as needed to loosen the sauce. Taste and season with salt only if preferred.
1 tbsp (14 g) unsalted butter, salt, 1 cup (240 ml) reserved pasta cooking water
Divide among serving bowls and top with green onions and sesame seeds. Sprinkle with the additional gochugaru, if desired, and serve with kimchi on top or alongside.
2 to 3 green onions, 1 tsp (3 g) sesame seeds, 1 tsp (2 g) Gochugaru (Korean pepper flakes), kimchi