Step 1

Peel and dice the potatoes. Wash and peel the sweet potatoes using a potato peeler. Next, dice the sweet potatoes into 1-inch cubes.

Step 2

Bring a pot of water to a boil. Bring a large pot of salted water to a boil. Once boiling, carefully add the diced sweet potatoes and boil them for 12-15 minutes or until tender. Once cooked, drain the sweet potatoes using a colander.

Step 3

Blend. Transfer the drained potatoes to a high-speed blender and add the 3 cups of water. Blend for 10-15 seconds or until smooth. You should end up with the consistency of a smoothie. Set aside.

Step 4

Slice the aromatics. Peel and slice the garlic, shallots, ginger, and galangal. Slice the white part of the lemongrass stalk into 1-inch slices. Transfer all of the aromatics to a high-speed blender.

Step 5

Blend into a purée. Add about 1/4 cup of water to the blender and blend for 10-15 seconds or until it forms a smooth paste.

Step 6

Sauté the aromatic paste. Heat the oil over medium heat in a deep pot or Dutch oven. Once hot, add the aromatic paste and fry it for 5-7 minutes, stirring regularly, until it appears dryer. The oil should also start to separate from the paste.

Step 7

Add the curry powder. Next, add the curry powder and stir to combine it with the paste. Cook for another 2 minutes. At this point, you can add some chili powder of ground dried chilies if you want some heat.

Step 8

Add the fermented bean paste and seasonings. To the pot, add the fermented bean paste, sugar, and salt.

Step 9

Pour in the blended sweet potatoes. Pour the blended sweet potato sauce into the pot and stir to combine with the aromatics. Finally, let the gravy simmer covered for about 10 minutes. Taste and adjust the sweetness and saltiness to your liking, and keep it warm while preparing the noodles and add-ins.

Step 10

Cook the noodles. Bring a large pot of water to a boil and cook the noodles according to the package instructions. Drain the noodles and divide them between serving bowls.

Step 11

Pour in the gravy. Pour a generous ladle of piping hot sweet potato gravy into each bowl.

Step 12

Garnish. Finally, before serving, garnish each bowl with a sprinkle of fried onions, sliced fried tofu or Youtiao, some chopped cilantro and scallions, and a few chili slices. Add a squeeze of lime as well.

Step 13

Enjoy! Using chopsticks, give it a good stir to allow the fried onions and fresh herbs to infuse the gravy before eating.

Step 14

You can keep the sweet potato gravy in the refrigerator for up to 4 days.