This light Japanese broth is poured over tender ramen noodles (fine, quick-cooking wheat noodles) and topped with seared tuna to make a healthy and delicious meal.
Heat the water and miso paste gently in a large saucepan, stirring until the miso has dissolved. Bring to a boil, then reduce the heat, cover, and simmer gently while preparing the remaining ingredients.
Cook the noodles according to the package directions, drain, and divide among 4 bowls. Season the tuna steaks with salt and ground black pepper, to taste. Brush a nonstick skillet with oil and heat until hot. Sear the tuna for about 2 minutes on each side until cooked, but still pink in the middle.
Place a tuna steak in each bowl and top with scallions. Ladle the broth into the bowls and serve immediately.