Yamakake Udon Recipe: Tips for Making Udon With Grated Yam

Yamakake udon is a preparation of sanuki udon noodles in dashi topped with grated Japanese mountain yam, served chilled or hot with an egg yolk for silky richness. Sanuki udon are thick, chewy Japanese noodles made from wheat flour, water, and salt, with a squarish shape that distinguishes them from other types of udon noodles. They are much thinner than buckwheat soba noodles and wheat ramen noodles.

This dish pairs sanuki udon with tororo, or grated yamaimo (Japanese mountain yam). When grated, yamaimo takes on a slimy, sticky texture—much like nattō (fermented soybeans) but without the funk. Placing a raw, golden egg yolk on top of the frothy, snow-white tororo creates a trompe l’oeil effect, mimicking a sunny-side-up egg.

For the best flavor, seek out frozen sanuki udon noodles, which often come preportioned. Here’s what else to know.

1. 1. Handling the yamaimo: Peel only as much Japanese mountain yam as you’ll use, rather than peeling the entire vegetable. Hold the yam with a paper towel or cloth clean while you grate it to prevent the slime from covering your hands.
2. 2. Preparing the dashi broth: Adjust the broth seasoning to your preference. A splash of fish sauce, dried chilies, sliced garlic and ginger, or a spoonful of miso make excellent additions.
3. 3. Cooking the noodles: Cook the udon in its own pot of salted water, rather than in the broth. As they cook, the noodles release starch, which can give the dashi a cloudy color and thicker consistency.
4. 4. Separating the egg: The easiest way to separate eggs is to use your fingers. In a small bowl, crack an egg and gently lift the yolk with your hand, letting the egg white strain through your fingers.
5. 5. Substituting ingredients: If you can’t find yamaimo at the market, try the similar nagaimo (Chinese yam) or even grated and strained daikon radish.
6. 6. Making chilled udon soup: To make hiyashi yamakake udon, the cold version of this dish, simply prepare and refrigerate the broth ahead of time and add chilled udon noodles. Cook the noodles as usual, then submerge them in cold water with ice cubes and strain. Garnish with your preferred toppings.