Recipe: 'Most Wanted' Dressing recipe and Experimenting in lieu of Unaquirable Ingredients

I've been wanting that orange dressing they put on your salad at Japanese restuarants for the longest time.  I've often said they should bottle this, or have considered asking if i could bring some home.  I'd had a feeling that this was something that had to be made fresh and eaten soon after... now I know.

I found a 'neat' and 'pretty' new website, which may soon become a favorite food blog: Scaling Back.  I also love this awesome and different looking treat recipe from this site.

Avocado salad with carrot ginger dressing
adapted from Martha Stewart
Serves 4
Ingredients:

• 2 medium peeled and grated carrots
• 1 small chopped shallot
• one 2-inch piece peeled and chopped shallot
• 2 tablespoons white miso
• 2 tablespoons rice vinegar
• 2 tablespoons sesame oil
• 1/4 cup water
• 1/4 cup vegetable oil
• salt and pepper to taste
• 1 head of bibb lettuce
• 1 avocado
• 1 bunch radishes
• 1 cup edamame

Method:

• Process carrots, shallot, ginger, miso, vinegar, sesame oil and water in a food processor or blender until smooth.
• With the machine running, slowly add vegetable oil.  Season with salt and pepper.
• To assemble the salad.  Break up the lettuce and divide among four plates.  Quarter the radishes and add them with the edamame to the salad.  Dice the avocado and scatter over the top.  Drizzle dressing over the top of the salad or serve on the side in a small bowl.

The problem here, besides the double shallot ?misprint is the obscurity ingredient list, obscure for someone who doesn't have a lot of experience in cooking let alone recipe reading.  Specifically, (and here giving full exposure to my duh-ness) I'm wondering about white miso.  Though I've never jumped off the cliff of uncertainty and actually bought miso from the store, I thought it came in a kind of powder that you reconstitute to make soup.  So, am I doing two tablespoons of powder -or paste or bar- or soup?  Could I possibly omit the miso? or find a substitute? Rice vinegar, sesame oil and shallots I don't usually have or get because they're expensive. 
The question is, how bad do I want it? In a world where my boss, my daughter's daycare director, my brother, my boyfriend, my mom (where have you been!) and the current state of my life in general are grating on my nerves and my mind goes back and for between an endless tirade of angry profanity and frustated to tears -pretty bad.