For the vegan egg yolk: Place 1/2 cup water in a blender. With the blender running, sprinkle in 3 teaspoons of Vegg egg yolk replacer. Blend for 30 seconds.
In a small sauce pan, combine 1/2 cup water and 2 tablespoons agar agar flakes. Bring to a boil and simmer for 5 minutes until the flakes are dissolved. Add the agar agar mixture to the Vegg mixture and blend again. Let this mixture cool completely and then let chill slightly. You want it to be cold but not totally set. Have a bowl filled with ice water at the ready. Dip a tablespoon in a little bit of oil. Then fill the tablespoon with the Vegg mixture. Slightly tilt the ice water bowl and submerge the filled tablespoon into the water, right side up. Just hold it there for about 2 minutes. The mixture will begin to set. You can lightly shake the spoon back and forth to loosen the Vegg yolk. Once set, gently tip it out of the tablespoon. Repeat to make more yolks. Let the yolks set in the ice water for about 30 minutes, while preparing your soup.
For the miso udon soup, heat 2 tablespoons olive oil in a large pot. Add in 1/2 onion, thinly sliced. Saute for about 3 minutes. Add in 8 cups of water and bring to a boil. In a small bowl add 4 tablespoons of organic white miso paste and 2 cubes of "Not-Chick'n" LOW SODIUM cubes. The regular ones are way too salty so it is important to use the low sodium. The soup would still taste great without these cubes, I just happen to have them and wanted to add some extra flavor. Pour about 1/2 cup of the hot broth over the miso and cubes. Whisk to break down. Add back into the soup along with 2 tablespoons soy sauce, 1/4 teaspoon sesame oil, and chili oil to taste. I added in 1/2 of a 12 ounce package of dried udon noodles. Bring to a low boil and cook 12 minutes. Meanwhile you prepare your toppings.
I used Miataki mushrooms, baby bok choy, sugar snap peas, small purple potatoes, organic tofu, thinly sliced seaweed, and black sesame seeds.
Quarter and wash 1 baby bok choy. Gently break up one cluster of miataki mushrooms. In a cast iron skillet, add about 1/4 cup of water. Lay the quartered bok choy, miataki mushrooms, about 1/4 cup sugar snap peas, a few thinly sliced baby purple potatoes, and some cubed tofu into the skillet. Turn the heat to medium and cover. Cook for about 15 minutes till the veggies are cooked through and lightly browned underneath. Halfway through, pour a couple tablespoons of soy sauce over the veggies. Cover and continue to cook the rest of the 15 minutes.
Ladle the broth and udon noodles into a bowl. Arrange your cooked veggies and tofu on top of the soup and right before serving, add in your sliced nori and top with the Vegg yolk. Just gently remove from the water using your hands and place in the soup.