Name: Miso-Butter Noodles with Caramelized Onions
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Ingredients: 4 small yellow onions, sliced into rings; 4 garlic cloves, minced; 1 tsp light soy sauce; 1 tsp honey; 2 tbsp white miso; 1 tbsp beef tallow; 2 packs wet udon noodles; 3 tbsp starchy noodle water; 3 tbsp unsalted butter; Chives, very finely sliced, for topping; Fried onions, for topping; White sesame seeds, for topping

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After being completely starstruck by my gochujang butter noodles with caramelized onions, I couldn’t stop thinking about that combination. There was something about the way deeply sweet onions melted into a rich buttery sauce that felt too good not to explore further. So naturally, I went in a totally different direction and landed here.

This version swaps the spicy kick for something softer and deeper. The onions slowly caramelize until they’re jammy and golden, the butter adds pure, rich comfort, and the white miso brings that savory fermented umami that makes you keep reaching for another bite. It’s cozy, rich, and surprisingly simple, with every thick udon noodle coated in a silky sauce that tastes like it took way more effort than it actually did.

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Easy Miso-Butter Noodles with Caramelized Onions Recipe

This buttery miso-butter noodles with caramelized onions is surprisingly approachable and perfect for an easy family dinner. After caramelizing the onions, loosening the miso with starchy noodle water, and tossing everything together with butter and udon, the result is a silky, savory-sweet bowl with chewy noodles, deep umami, and plenty of texture from the toppings.

Ingredients for Miso-Butter Noodles with Caramelized Onions

Yellow onions: Bring mellow sweetness and a soft, jammy texture as they caramelize. You can substitute white onions if needed, since they give a similarly mild sweetness.
Garlic cloves: Add savory depth and a fragrant finish to the buttery onion mixture.
Light soy sauce: Adds salt and savory depth to the miso mixture.
Honey: Adds a touch of sweetness that rounds out the savory miso and soy sauce. You can substitute maple syrup or dark brown sugar for a similar sweetness and consistency.
White miso: Provides fermented umami depth and helps create the savory sauce coating the noodles. You can substitute red miso for a slightly stronger flavor.
Beef tallow: Gives the onions a rich base for caramelizing. You can substitute even more unsalted butter if you want it even richer.
Wet udon noodles: Bring the chewy, substantial noodle texture that makes this dish so satisfying. You can use your favorite noodles, we just love udon a lot 🙂
Starchy noodle water: Loosens the miso mixture into a sauce and helps it coat the noodles evenly.
Unsalted butter: Adds richness and helps bring the caramelized onions, garlic, and miso together. You can use salted butter too, but then I recommend leaving out the light soy sauce or else the dish may be too salty.
Chives, very finely sliced, for topping: Add a fresh, lightly oniony contrast to the rich noodles. You can substitute finely sliced green onions for a similar fresh finish.
Fried onions, for topping: Add crisp texture and a savory crunch. You can substitute crispy shallots or garlic for a similar effect.
White sesame seeds, for topping: Add a gentle nuttiness and a little extra texture. You can substitute black sesame seeds if preferred.

How to Make Miso-Butter Noodles with Caramelized Onions

Step 1: In a bowl, combine the light soy sauce, honey, and white miso until you have a paste-like mixture.

Step 2: Heat 1 tablespoon beef tallow over medium heat, (my stove was set to 5.5), then add the onion rings. Stir-fry for 25 to 30 minutes, stirring regularly, until the onions are deeply caramelized and softened.

Step 3: Toward the end of caramelizing the onions, bring a separate pot of water to a boil and cook the wet udon noodles.

Step 4: Collect 3 tablespoons of starchy noodle water and add it to the bowl with the miso paste, stirring to turn it into a smooth sauce.

Step 5: Melt the unsalted butter into the caramelized onions and add the minced garlic. Stir fry for 1 minute.

Step 6: Once the butter has melted and the garlic is fragrant, add the miso sauce and toss the cooked noodles into the miso-onion sauce until every noodle is well coated.

Step 7: Serve in your favorite bowl and top with chives, white sesame seeds, and fried onions. I added a drizzle of miso rayu.

Substitute Beef Tallow with More Butter

More unsalted butter works well in place of beef tallow because it can provide the cooking fat needed to caramelize the onions without changing the basic technique. Use the same 1 tablespoon amount and cook the onions over medium heat as directed.

The main change will be flavor. Beef tallow gives the onions a richer, meatier character, while butter lets the miso, butter, and caramelized onions come through with a rounder, milkier sweetness. The onion texture and caramelization timing should remain similar, though butter can brown and catch a bit faster than tallow, so keep an eye on the heat toward the end.

Tips for Making Miso-Butter Noodles with Caramelized Onions

Tip 1: Give the onions their full caramelizing time. The 25 to 30 minutes is what develops their soft texture and mellow sweetness, so avoid rushing this part.
Tip 2: Adjust the butter amount to taste. Use a little less for a lighter dish, or add more if you want the sauce extra rich and glossy.
Tip 3: Try swapping in part ghee. Replacing some of the butter with ghee adds a deeper, nuttier flavor while keeping the same silky texture.
Tip 4: Stick with unsalted butter. The sauce already gets plenty of salt from the soy sauce, so using unsalted butter keeps you in control of the final seasoning.

Make-Ahead Instructions

The caramelized onions and miso sauce can be prepared in advance, up to 2 days ahead. Store them covered in the refrigerator and prepare the udon when ready to serve.

The flavors of the caramelized onions and miso can become stronger as they rest, although the freshly cooked noodles will have the best texture.

Storing Leftovers

Store leftover noodles in an airtight container in the refrigerator for up to 3 days.

The udon will soften as it sits, and the fried onion topping may also lose some of its crispness, so adding fresh toppings after reheating will give the best texture.

Freezing Instructions

Freezing is not recommended, because the cooked udon and creamy miso-butter sauce may lose their original texture after thawing.

Reheating Instructions

Reheat leftovers gently in a skillet over low-medium heat, stirring until warmed through. If the noodles have tightened up in the refrigerator, add a small amount of water to loosen the sauce.

Avoid high heat, which can make the noodles overly soft while reheating.

Serving Suggestions

Serve these noodles hot in your favorite bowl with the specified chives, white sesame seeds, and fried onions scattered over the top.

This is a cozy option for a weeknight family dinner, a low-effort lunch, or any meal when you want something warm and comforting without making a complicated spread.

Miso-Butter Noodles with Caramelized Onions