Bring a large pot of water to a boil. Add dasima and steep for a few minutes to create a light broth. Remove kelp before water reaches a rolling boil.

Season the broth with salt. Add pasta and cook until just shy of al dente, according to package instructions.

In the last few minutes of pasta cooking, add asparagus to the pot and cook until tender-crisp.

Reserve 1 cup of dasima broth, then drain the pasta and asparagus.

Return pasta and asparagus to the pot. Add heavy cream, a splash of reserved broth, and rice vinegar.

Cook over medium heat, stirring, until the sauce thickens and coats the pasta.

Drizzle with sesame oil, season with salt and pepper, and toss to coat evenly.

Plate the pasta and sprinkle with crumbled roasted seaweed. Serve immediately, with grated Parmesan if desired.