Zucchini Soup

Bahan-bahan (4 porsi)

• 1 ½ pounds zucchini (about 2 medium)
• 1 tablespoon butter
• 1 small onion (diced)
• 2 cloves garlic (minced)
• 2 ¼ cups chicken broth (not low sodium)
• salt and black pepper (to taste )
• ½ cup heavy whipping cream
• sour cream (and fresh dill for garnish )