Cream of Onion Soup

Bahan-bahan (4 porsi)

• ⅓ cup butter
• 1 pound sweet onions (cut into ¼" slices )
• 3 ribs celery ( finely chopped)
• ⅓ cup all-purpose flour
• ¼ teaspoon dried thyme leaves (or 1 sprig fresh thyme)
• 3 cups chicken broth
• ¾ cup heavy whipping cream
• salt and pepper to taste