Can I cook my haggis from frozen?
You 'can' cook it from frozen, knowing that a few things will suffer. First, the outside will be somewhat dried out and over-cooked before it is done in the center, depending on how hot the oven is and the cooking time. That being said, if your Haggis is pre-cooked, it should be OK.

You can also 'Hurry up ' the defrosting process by putting it under running water. This can affect texture, depending on what you are defrosting.

Finally, you can speed-defrost something by using warm running water, but this carries SOME SERIOUS RISK if you don't cook it right away. The bacteria will love the warmth and will start to multiply, but I have done this many times when I knew I was using a meat immediately.