Combine water, chicken stock, or vegetable stock in a large pot
Add aromatics such as garlic, ginger, and onion
Add kombu, dried shiitake mushrooms, or bonito flakes if desired
Bring to a gentle simmer
Skim off any foam or impurities
Simmer for 30 minutes to 4 hours, depending on desired depth of flavor
Add soy sauce, miso, salt, or tare to season the broth
Strain out solids
Keep the broth hot until serving
Pour over cooked ramen noodles and toppings