In 1908, Japanese chemist Kiku­nae Ikeda discovered that an amino acid called glutamate, found in kombu, or dried kelp, was responsible for the wonderful savoriness in his wife’s dashi, a stock that forms the basis of many Japanese dishes.

Because that unique flavor was not salty, sweet, sour or bitter, Ikeda called this fifth taste “umami,” which roughly means “essence of deliciousness.” There is no perfect English translation.

Today, when we talk about umami in home cooking, we often think of the loud savoriness of, say, a tomato sauce imbued with anchovies or deeply caramelized onions. Meatiness also comes to mind: Umami is a specific taste that our tongues perceive when coming into contact with foods rich in glutamates, like grilled steak. It is found in dishes anchored to miso, mushrooms and fish sauce as well, where it detonates with the kind of big flavor that’s a reminder of the inherent goodness of eating.

But one thing to know: Umami doesn’t always land like a bomb. Taste its subtlety in green vegetables like broccoli and asparagus, or in leafy kale, roasted until crisp like potato chips. The soft umami of dried seaweed — as in a balanced dashi — floats on the tongue with gentle savoriness. Salt can accentuate its very best features.

In Korean cooking, kelp is essential to building layers of umami, the kind that lingers. Dried seaweed is rehydrated into long, diaphanous tangles for a soup called miyeokguk. Jumeokbap — “fist rice” — are soul-soothing, seaweed-flecked rice balls that can relieve a tired parent trying to feed a picky child. Dasima (kombu in Japanese) is a dried kelp product boiled with anchovies to make yuksu, an umami-rich stock.

In this dish, thick tubes of chewy rigatoni are boiled in a quick dasima yuksu, without the anchovies, which both seasons and thickens the cream sauce. Onyx-black filaments of gim (Korean roasted seaweed often sold as ready-to-eat snacks) are showered over the finished pasta. Gim adds a nutty, saline note — an indelible savory quality — that takes the feel and flavor of this dish into shrimp Alfredo territory.

When umami quietly hums like that, full of nuance, each comforting bite builds upon the last. It’s hard to translate that sensation into words, but “flavor balm” comes close.

CREAMY ASPARAGUS PASTA

• 20 grams gim (Korean roasted seaweed) or nori (Japanese roasted seaweed)
• 2 (4-inch) squares dasima or kombu (dried kelp)
• 8 cups cold tap water
• 1 tablespoon kosher salt
• 1 pound dry rigatoni
• 1-1/2 cups heavy cream
• 1 small red onion, halved and thinly sliced
• 2 large garlic cloves, finely grated
• 1 teaspoon freshly ground black pepper, plus more to taste
• 1 teaspoon rice vinegar
• 1/2 pound asparagus, thinly sliced at an angle
• 1 tablespoon toasted sesame oil
• Flaky sea salt, for serving

Fold the gim in half and, with very sharp kitchen shears or a chef’s knife, slice into thin strips. Set aside for serving.

In a large pot, combine 1 dasima square with water. Bring to a boil and season with salt. Add pasta and cook for half the time the package tells you is al dente. Reserve 1 cup pasta water, then drain pasta and return it to the pot. (Discard dasima.)

Add remaining dasima square, cream, onion, garlic, pepper and reserved pasta water. Bring to a boil over high heat, then immediately reduce heat to maintain a gentle simmer. Stirring occasionally, cook pasta until the onion-infused cream has thickened significantly, thinly coating the noodles, 4 to 5 minutes.

Turn off heat. Add vinegar and asparagus; stir 1 minute to combine. The residual heat from the pasta will gently cook asparagus to tender-crisp. Stir in sesame oil and season with more pepper, if desired.

Divide pasta among serving dishes, discarding dasima. Shower with reserved gim and sprinkle with flaky sea salt. Serve immediately, before gim wilts and turns soggy. Serves 4.

Nutrition information unavailable.

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