The time it takes to toast a sandwich in an oven can vary depending on several factors, including the type of oven, the temperature setting, the thickness of the sandwich, and the ingredients inside. As a general guideline, it typically takes about 10 to 15 minutes to toast a sandwich in a preheated oven at 350°F to 400°F (175°C to 200°C).
However, it's important to keep an eye on the sandwich while it's toasting to prevent it from overcooking or burning. The exact time may differ, so it's recommended to check on the sandwich after about 5-7 minutes and then monitor it closely until it reaches your desired level of toasting or until the cheese inside (if applicable) has melted and the bread is golden brown. Adjust the cooking time as needed based on your preferences and the oven's performance.
Always follow any specific instructions provided by a recipe or cooking guide, if available, for best results.