Shrimp and crab chowder

It's dungeness crab season here in California, and I'm trying to make the most of it. For this chowder (which served 2 people), I picked the meat from 1 crab that was a little over a pound. I used the shells, along with shrimp shells and lobster shells, to make a stock for the base of the chowder.

I sauteed some onions and garlic in a little butter, and added a small amount of flour as a thickener. I added the stock and 2 peeled, diced potatoes. The soup simmered until the potatoes were tender. Then I added about 1 cup of medium sized shrimp, the crab meat, and 1/2 cup of frozen corn. After the shrimp were cooked through, I took the chowder off the heat and added some fresh chopped dill.