Stone Crab Johnny Cakes with Grainy Mustard Vinaigrette

Name: Stone Crab Johnny Cakes with Grainy Mustard Vinaigrette
Ingredients: 3/4 cups stone ground yellow cornmeal; 1 1/2 teaspoons kosher salt; 1 teaspoon granulated sugar; 1 1/4 cups boiling water; 4 tablespoons unsalted butter; 2 tablespoon grainy mustard; 1 tablespoon Dijon mustard; 3 tablespoons white wine vinegar; 2 tablespoons chopped fresh tarragon; Kosher salt and freshly ground black pepper; Honey, to taste; 1/2 cup extra virgin olive oil; 2 tablespoons canola oil; 2 pounds stone crabs, meat removed from shells and coarsely chopped; 1/4 cup thinly sliced green onion (green and pale green part); 3 tablespoons chopped fresh cilantro; Tarragon leaves, for garnish