Miso and dashi are both gluten free (though please double check the label of whatever you purchase). Instant dashi does contain MSG, so if you're concerned about that, make the dashi from scratch or leave it out entirely and add in an additional teaspoon or so of soy sauce.
For the broth, use pork-based or vegetable broth. Chicken and beef are too strong in flavor for this soup.
10 oz (285 g) dried ramen noodles
1/2 cup (200 g) fresh or canned bamboo shoots, sliced
1/2 cup (170 g) fresh or canned corn kernels, drained
1/3 cup (80 g) defrosted frozen or fresh spinach
8 cups (2 liters) store-bought or homemade pork or vegetable broth
2 teaspoons instant dashi granules
1 tablespoon soy sauce, or to taste
4 tablespoons fresh miso paste
1 cup (100 g) fresh bean sprouts
1 stalk green onion (scallions), finely chopped
4 teaspoons chili oil (optional)
Place the whole, un-cracked eggs in a medium pot and fill with water to cover eggs by 1 inch (2.5 cm). Turn the heat to high and when boiling, turn the heat off and let the eggs sit in the hot water for 10 minutes. Promptly use a slotted spoon to remove the eggs and peel the egg under cold running water. Slice each egg in half.
Return the same pot of water to a boil. Add the ramen noodles and cook according to package instructions (most ramen noodles only take 3 minutes to cook.) Drain and rinse with cold water to stop the cooking.
Divide the noodles, hardboiled eggs, bamboo shoots, corn and spinach among 4 large serving bowls.
In a large pot, add the stock, instant dashi and soy sauce. Bring to a boil over high heat. Remove from the heat and stir in the miso. Taste the soup and add an additional 1 to 2 tablespoons of miso if you’d like. Ladle soup into each bowl. Top each bowl with fresh bean sprouts, green onions and a drizzle of chili oil, if desired.