Step 1

In a medium saucepan, combine cold water and kombu; bring to simmer over medium heat. Remove from heat and stir in bonito flakes; let stand 5 minutes. Using a fine mesh strainer, strain out and discard solids (or reserve for a second use).

Step 2

Return liquid (dashi) to saucepan and add pork broth, chicken broth and ginger. Add both miso pastes to a sieve and set just below the surface of the broth; use the back of a spoon to work the miso through the sieve, dispersing it into the broth. Cook and stir over medium heat, until mixture comes to a simmer. Serve immediately (see post for assembling a miso ramen bowl) or cool and refrigerate for up to 1 week or freeze for up to 1 month.