Prepare the mushroom stock: Combine dried shiitake mushrooms, kombu, and water in a pot.

Bring the water to a near boil, then reduce heat to a simmer.

Simmer for 5 minutes to infuse the flavors.

Remove the pot from heat and let it sit for 3 minutes to further develop the stock.

Strain the stock through a fine-mesh strainer to remove solids and set aside.

Create the soup base: Heat sesame oil in a large skillet or wok over high heat.

Add sliced crimini mushrooms and stir-fry for approximately 20 seconds.

Drizzle the remaining sesame oil, then add finely chopped garlic and crushed red chili flakes.

Continue stir-frying for another 20 seconds until fragrant.

Pour the mushroom stock through a fine-mesh strainer directly over the pan.

Discard the solids caught in the strainer.

Adjust the heat to maintain a gentle simmer.

Divide freshly cooked ramen noodles into individual serving bowls.

In a separate small bowl, mix shiro miso and aka miso.

Ladle some hot stock from the pan into the bowl with the miso.

Whisk the miso pastes and broth together until it is smooth.

Add the miso mixture to the simmering stock in the pan.

Turn off the heat and ladle the broth over the noodles in each bowl.

Garnish with fresh cilantro leaves and serve immediately.