From Esther Choi: "We serve this at mŏkbar in the summer. It’s a dish I grew up eating with my grandma, kongguksu. The beauty of it is that it’s so simple: just a few ingredients, completely vegan. I use special noodles at the restaurant: They’re a mix of wheat and buckwheat, which gives it more of a bite than the traditional white noodles you’d ordinarily find in kongguksu. Then I make a soybean broth from soybeans imported from Korea, blend that together with regular toasted sesame seeds and wild sesame seeds—you know, deul ggae—plus really good water. When you’re using so few ingredients, and the broth is so simple (it’s literally fresh soy milk), the kind of water you use makes a big difference." —Food52
Prepare the noodles according to package instructions and set aside to cool, then chill.
Place all the ingredients for the broth in a blender at full blast until very smooth and broth-like.
In boiling water, blanch the tomatoes for 30 seconds and place in an ice bath. Peel each tomato and discard their skins. Mix them with the garlic oil and salt, and place evenly on a sheet tray. Roast at 250° F for 1 hour and chill thoroughly.
To assemble, place the chilled noodles into bowls, add a pint of broth to each portion, and top with the cucumbers, roasted tomatoes (plus some oil), and the wild sesame seeds. Taste and add more salt if you feel it needs it.