This mustard paste buckwheat noodle salad is a popular dish in the northwest region of China. The freshly made mustard paste and homemade chili oil adds pungent tastes to the salad. It’s one of my favorite salad recipes for summer.
Have you noticed that I used the word “buckwheat noodle” instead of “soba noodle”? You probably also noticed that my buckwheat noodles are significantly yellower than soba. There’s a reason.
Typically, Japanese soba noodles are made from of a mixture of buckwheat and wheat flour. The gluten in wheat flour adds stickiness to the dough so it holds together well. I only found one brand of a gluten-free version of soba noodles (from Eden Food, Inc.) at my local grocery stores. No doubt, you could certainly substitute these for this recipe.
In this recipe, the darker and smoother buckwheat noodles are made from 100% buckwheat that are treated with limewater, a.k.a calcium hydroxide. It’s a nixtamalized dough, like masa. This step dramatically improved the chewy texture, flavor, and aroma of buckwheat. It also makes the dough stickier and easier to handle when making noodles with a special tool.
To be clear, buckwheat is a kind of seed and is naturally gluten-free. The “wheat” in the name doesn’t mean it’s related to the wheat family.
This type of buckwheat noodles is very popular in my hometown, Xi’an, China. If you ever make your way out to see the famous Terracotta Warriors in Xi’an, make sure to stop at a local restaurant and give it a try. It’s called Heluo (pinyin) in Chinese. However, these nixtamalized buckwheat noodles are well known only in specific areas in northwest China such as Xi’an.
These cold buckwheat noodles taste best when served with the freshly made yellow mustard paste. It’s super easy to make your own mustard paste for this recipe. All you need to do is pour boiling water over some freshly ground mustard powder (from brown seeds) and let it steep for a few minutes to release all the pungent flavor and aroma.
Although you may not find these nixtamalized buckwheat noodles anywhere here in the US (I got mine from China), you can definitely use any kind of whole grain noodles for this Asian flavor twist. I’m eager to experiment in making these nixtamalized buckwheat noodles at home. I’ll keep you updated if I have any success. Fingers crossed!

- ½ tablespoon brown mustard seeds
- 3 tablespoons boiling water
- 1 pound cooked buckwheat noodles or soba
- 2 tablespoons canola oil
- 1 tablespoon soy sauce
- 2 cloves garlic grated
- ½ tablespoon chili oil
- 1 teaspoon sesame oil
- ¼ teaspoon salt
- 4 tablespoons water
- ½ tablespoon mustard paste
- ½ seedless cucumber shredded or spiralized
- ½ tablespoon cilantro leaves chopped
- Grind mustard seeds in a coffee grinder into powder. Transfer the powder into a small glass jar. Pour boiling water over and cover the jar tightly with a lid. Steep for 5 minutes until the mustard paste is fragrant and pungent.
- Follow the package instruction to cook buckwheat noodles or soba noodles. After rinsing the cooked noodles with cold water, use a salad spinner to remove extra water. Transfer the noodles into a large salad bowl. Add canola oil and gently toss to let the oil coat the noodles evenly.
- Mix together all the dressing ingredients.
- Add the dressing, cucumber, and cilantro into the prepared buckwheat noodles and gently toss. Serve immediately.

I have never tried Buckwheat noodles but, as a pasta fanatic who is giving up gluten with my husband (because of his health issues), I am eager to find alternatives that I enjoy just as much! This recipe looks fantastic 🙂