Use a short fictional cafe menu to practice an order: "Could I have a small tea, please?" Add the choice that matters: "With milk on the side." The order is easier to follow when the main item comes before optional details.
If a requirement is important, ask directly. "Does this sandwich contain nuts?" asks about an ingredient. "Can you prepare it without contact with nuts?" asks a different question about preparation. Do not treat those answers as interchangeable.
Confirm rather than infer
In a role-play, the server might say, "I need to check with the kitchen." Reply, "Thank you. Please check before I order it." For a real serious allergy or other health requirement, use the appropriate established precautions and do not rely on a casual practice phrase alone.
Practice ordinary corrections too. Server: "One large tea?" Customer: "A small one, please." A direct correction prevents an avoidable mistake without requiring an elaborate apology.
Finish by checking the practical arrangement: "Is that to take away?" or "Where should I collect it?" Change roles and introduce one unavailable item so the customer must choose an alternative. The exercise develops clear requests and useful confirmation, rather than memorizing a perfect order that works only when the conversation follows a script.