Sour & Spicy Sweet Potato Noodles (Suan La Fen)

Three different ingredients make these hot-and-sour sweet potato noodles quite spicy. One of them, the green Sichuan peppercorns, can be tough to find and there isn't an easy sub, so leave them out if you like.

Prep Time:
25 mins
Total Time:
25 mins
4 servings


  • 4 cups low-sodium chicken broth

  • 1 cup water

  • 3 tablespoons chili oil with flakes (see Tips), well mixed

  • 2 tablespoons Zhenjiang black vinegar (see Tips)

  • 1 tablespoon reduced-sodium soy sauce

  • 1-2 teaspoons Sichuan peppercorn oil (see Tips)

  • 1 teaspoon toasted sesame oil

  • ¼ teaspoon kosher salt

  • Pinch of ground green Sichuan peppercorns (optional; see Tips)

  • 8 ounces sweet potato glass noodles (see Tips)

  • 8 cups coarsely chopped Chinese greens, such as yu choy or gai lan, or collards or kale

  • 2 tablespoons peanut or canola oil

  • 4 large eggs

  • Fried peanuts, fried soy nuts, fresh cilantro and/or sliced scallions for garnish


  1. Bring a large pot of water to a boil over high heat. Bring broth and 1 cup water to a boil in a large saucepan over high heat.

  2. Meanwhile, combine chili oil with flakes, vinegar, soy sauce, peppercorn oil, sesame oil, salt and green Sichuan pepper (if using) in a small bowl. Set aside.

  3. Cook noodles in the boiling water until soft, 6 to 8 minutes. Drain.

  4. Cook greens in the boiling broth until tender-crisp, 1 to 2 minutes. Cover and remove from heat.

  5. Heat peanut (or canola) oil in a large nonstick skillet. Crack in eggs, one at a time, and cook until the whites are firm and the yolks are still slightly runny, 2 to 3 minutes.

  6. Divide the chili oil mixture among 4 shallow bowls. Top each with the noodles, the greens and their broth, and an egg. Garnish with peanuts, soy nuts, cilantro and/or scallions, if desired. Serve hot.


Tips: Sichuan chili oil: A Sichuan spice blend is infused into the oil, which is mixed with chile pepper flakes (not fried). The oil can be strained and the flakes used separately.

Zhenjiang black vinegar: Sometimes labeled "Chinkiang," this delicately sour rice vinegar seasoned with sugar and salt is used in virtually all cold Sichuan noodle and vegetable sauces, and in other sweet and sour dishes.

Sichuan peppercorn oil: A fragrant finishing oil infused with essential oils extracted from the Sichuan peppercorn. It has a smoother taste than the whole spice yet enough zing to wake up the mouth.

Green Sichuan peppercorns: With a distinctly lemony taste that is different from red Sichuan peppercorns, green ones complement fish, chicken and vegetables. China has only recently started to export them, so they are a little harder to find.

Sweet potato glass noodles: Long, clear, chewy noodles made from sweet potato starch. While bland on their own, the noodles absorb the flavors of whatever they're cooked in.

Nutrition Facts (per serving)

508 Calories
27g Fat
54g Carbs
13g Protein
Nutrition Facts
Servings Per Recipe 4
Serving Size 2 2/3 cups soup & 1 egg
Calories 508
% Daily Value *
Total Carbohydrate 54g 20%
Dietary Fiber 2g 8%
Total Sugars 2g
Protein 13g 27%
Total Fat 27g 35%
Saturated Fat 5g 25%
Cholesterol 186mg 62%
Vitamin A 1711IU 34%
Vitamin C 41mg 46%
Folate 111mcg 28%
Sodium 426mg 19%
Calcium 146mg 11%
Iron 3mg 17%
Magnesium 26mg 6%
Potassium 621mg 13%

Nutrition information is calculated by a registered dietitian using an ingredient database but should be considered an estimate.

* Daily Values (DVs) are the recommended amounts of nutrients to consume each day. Percent Daily Value (%DV) found on nutrition labels tells you how much a serving of a particular food or recipe contributes to each of those total recommended amounts. Per the Food and Drug Administration (FDA), the daily value is based on a standard 2,000 calorie diet. Depending on your calorie needs or if you have a health condition, you may need more or less of particular nutrients. (For example, it’s recommended that people following a heart-healthy diet eat less sodium on a daily basis compared to those following a standard diet.)

(-) Information is not currently available for this nutrient. If you are following a special diet for medical reasons, be sure to consult with your primary care provider or a registered dietitian to better understand your personal nutrition needs.

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