Fill a medium-sized saucepan with water and bring it to a boil. Drop the carrots and one tablespoon of salt into the boiling water. Blanch the carrots for 30-60 seconds (depending on how cooked you like them) and then lift them out with a slotted spoon or small strainer. Run the carrots under cold water to stop the cooking and then empty them into a medium-sized bowl.
Let the water come back to a boil and add the bok choy. Blanch for 30 seconds and then remove using a slotted spoon or small strainer. Run them under cool water and then add them to the carrots.
Let the water come to a boil again and cook the soba noodles according to package instructions (usually 5-8 minutes, until al dente). Strain the noodles, cool them down, and add them to the bowl with the carrots and bok choy. Add the scallions and cucumbers to the bowl and toss everything gently together.
Whisk together the sesame oil, rice vinegar, soy sauce, and hot sauce (if using). Pour this over the noodles and vegetables, and then toss until everything is evenly coated.
If cooking eggs, empty all but 4 inches of the water and let it come back to a gentle simmer. Crack the eggs into individual measuring cups. Add a splash of white vinegar to the water and slip the cracked eggs in one at a time. Poach for 4 minutes for soft boiled eggs or 5 minutes for a firmer yolk. Strain and set aside until serving. (Here's a full video on how to do this)
Divide salad into individual bowls and add a poached egg to each bowl. Salad can be served warm or cold, and it can keep refrigerated for about 3 days.