Cream of Pecan Soup

• 2 tablespoons butter
• 1/2 cup diced onion
• 1/2 cup celery leaves
• 1 tablespoon all-purpose flour
• 2 cups chicken broth
• 2 teaspoons soy sauce
• Dash of ground nutmeg
• 1 cup pecans, ground fine in the blender
• 1-1/2 cups half-and-half
• 4 sprigs of mint