
There's triple the chickpea in this quick and comforting soup: The broth is flavored with chickpea miso, and the mix of soft and crispy chickpeas makes for a delightful mix of textures.
Heat ¼ cup vegetable oil in a large heavy-bottomed pot over medium-high. Pat dry a heaping ½ cup rinsed chickpeas (from two 15.5-oz. cans) and add to pot (stand back to avoid pops and splatters). Cook, stirring often, until chickpeas are golden brown with crisp outer shells, about 3 minutes. Remove pot from heat. Using a slotted spoon, transfer chickpeas to a plate, leaving oil behind. Season chickpeas with kosher salt and nutritional yeast; set aside.
Return pot to medium-low heat. Add 1 large onion, finely chopped, and cook, stirring often, until softened and translucent, about 3 minutes. Add one 2" piece ginger, finely grated, and 4 garlic cloves, finely grated, and cook, stirring, until fragrant, about 1 minute. Add ¼ cup nutritional yeast and 1–2 Tbsp. chickpea miso or yellow miso (see headnote) and cook, stirring to coat, 30 seconds. Add 6 cups water, 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt, and remaining chickpeas and bring to a boil. Reduce heat, partially cover, and simmer gently, stirring occasionally, until flavors have melded, 15–20 minutes.
Meanwhile, if using dried noodles, cook one 8–10 oz. package dried udon or other wheat noodles in a medium pot of boiling salted water according to package directions. Drain and rinse under cold water.
Add 8 oz. broccolini, halved lengthwise if thick, to broth and cook until bright-green and tender, about 2 minutes. Add cooked noodles or 16 oz. fresh wheat noodles and cook until heated through (and cooked, if using fresh noodles), about 2 minutes. Remove from heat and stir in 1 tsp. unseasoned rice vinegar. Taste soup and season with more salt and vinegar if needed.
Divide soup among bowls. Top with cilantro leaves with tender stems (if using), chili oil, and reserved chickpeas.