Step 1

In a large saucepan or Dutch oven, heat 2 tablespoons oil over medium-high heat until shimmering. Add shiitake, season with salt, and cook, stirring occasionally, until mushrooms have released their water and are starting to brown all over, about 4 minutes. Transfer shiitake to a plate and keep warm.

Step 2

Add remaining 2 tablespoons oil to saucepan, then add onion, ginger, and garlic. Cook, stirring up any brown bits on bottom of saucepan, until onions are soft and translucent, about 5 minutes.

Step 3

Add stock and bring to a simmer. Stir in kimchi and its liquid, miso, and soy sauce and return to a simmer. Season with salt, if needed.

Step 4

Meanwhile, if using angel-hair pasta, add baking soda to 4 quarts of boiling salted water; otherwise, omit baking soda and bring 4 quarts of plain salted water to a boil. Cook noodles until al dente; drain completely.

Step 5

Transfer noodles to bowl and spoon kimchi broth on top. Top each bowl with 2 egg halves, reserved shiitakes, scallions, nori, and watercress. Serve right away.