How long do you cook 1.2kg top sirloin roast?

I can't tell you exactly how long to cook your 1.2kg top sirloin roast without knowing your desired level of doneness.

Here's why, and what you need to consider:

* Doneness: Do you want it rare, medium-rare, medium, or well-done? Each level of doneness requires a different internal temperature.

* Cooking method: Are you roasting it in the oven, grilling it, or using a different method? Each method affects cooking time.

* Oven temperature: The temperature of your oven significantly impacts cooking time.

To help you figure out the cooking time, I recommend the following:

1. Decide on your desired doneness: Use a meat thermometer to determine the safe internal temperature for your preferred level of doneness.

2. Choose your cooking method: This will determine the general time range for cooking the roast.

3. Consult a reliable recipe: Find a recipe for cooking top sirloin roast using your chosen method and desired doneness. Many recipes include specific cooking times based on the roast's weight.

Important Note: Always use a meat thermometer to ensure your roast is cooked to a safe internal temperature.

Let me know if you have more details about your cooking method and desired doneness, and I can provide a more specific estimate!