All you need are udon noodles and broth. This soup is my all-time favorite because it's healthy, filling, warm, and able to be personalized. See my other recipes for dashi stock. OR dissolve instant dashi stock. OR just use chicken stock.
Open udon noodles. Boil in water for about 5 minutes until cooked. Drain. Rinse. Set aside.
Boil the spinach for 30 seconds. Drain. Cut the spinach into 2-inch pieces; the leeks into 1-inch diagonal slices; and the chicken breast into 4 equal slices.
Divide the udon into four bowls. Arrange the spinach, leeks, chicken, kamaboko, and mushrooms on top of the noodles, around the sides. Pour the boiling stock equally into the bowls.
Optional: Traditional udon has a raw egg in the center of the soup, but I don't like eating eggs. Chicken breast, kamoboko, mushrooms, spinach, and leeks CAN be omitted if you're desperate, but it won't be as filling.