Heat a deep, medium saucepan over high heat. Add the butter, leek and garlic and cook, stirring, for 5 minutes or until the leek is tender. Add the broccoli and stock, bring to the boil and cook for 8–10 minutes or until the broccoli is tender. Add the spinach and cook for a further 1–2 minutes. Use a hand-held blender to blend the soup until smooth. Stir in the cream, lemon juice, salt and pepper. Ladle into bowls and top with ricotta to serve. Serves 4.