Step-by-Step Instructions

• Preheat your oven to 375–400 °F (190–200 °C). Slice the top off the head of garlic and drizzle with olive oil. Season with salt and pepper, wrap in foil, and roast for 40–45 minutes.
• While the garlic is roasting, bring a large pot filled with water to a boil. Add the chopped potatoes and cook until fork-tender, about 15-20 minutes. Drain and set aside.
• In a large pot or Dutch oven, melt 4 tablespoons of butter over medium heat. Add the chopped onions and leeks, and sauté for about 5-7 minutes until softened.
• Decrease the heat and stir in the flour, cooking for 1 minute. Gradually whisk in the broth, milk, cream, and thyme, stirring until the mixture thickens slightly.
• Add the cooked potatoes and roasted garlic to the pot. Sprinkle in the Parmesan cheese and blend the soup until smooth. Adjust thickness with more broth if needed.
• Butter one side of each slice of bread and pile on the Gruyère cheese on the unbuttered sides. Cook in a skillet over medium heat for about 5 minutes on each side until golden brown and melted. Cut into crouton-sized pieces.
• Ladle the soup into bowls, garnish with chives and extra Parmesan cheese, and top with grilled cheese croutons before serving.