Heat a large pot over medium heat and add a splash of oil. Sauté the chopped onion, minced garlic, and minced ginger for 3–4 minutes. Stir in miso paste and diced tomatoes, simmer for 2 minutes. Pour in water and bring to a gentle boil, then reduce to low heat and simmer for 15 minutes.

Prepare chicken breast; marinate if desired. Heat skillet over medium-high heat, add oil, and cook chicken for 6–7 minutes on each side until golden brown. Slice chicken into strips and set aside.

In a separate pot, bring water to a boil and cook ramen noodles according to package instructions (3–4 minutes for fresh noodles). Drain noodles and rinse under cold water to stop cooking.

Layer ramen in bowls, add a generous serving of noodles, ladle hot miso broth over noodles, and arrange sliced chicken on top with assorted vegetables.

Consider adding a soft-boiled egg and a drizzle of soy sauce or chili paste to each bowl before serving. Enjoy!