"tastes mosly like liver"
yes that will be a predominant taste. On the east coast Mid Atlantic region we have scrapple a breakfast item made from pork scraps and liver, corn and whole wheat meal, broth from boiling the head, and fat. It is fried. It is a normal PA NJ DE farm country thing. I love it. It is a breakfast Pate. great with eggs ssu, and fried potatoes and onion.
Many Brits love grilled Kidneys with their eggs, or kippers (smoked herings)
These are traditional "stong flavored" foods.
But a good haggis has a blend of flavors, texture, subtle depth, and will accompany vegetables, condiments, without loosing itself.
Personally, I would like to have it with deep greens sauteed, mustard vinaigrette, beans cooked in garlic, stock, and tomato. However, where I've had it, mmore ordinary components were provided...some of which I didn't think were appropriate (Pub sauce, Worcestershire, Catsup, Colemans, Horseraddish.)
THe Alton Brown recipe is quite good if you can get the ingredients...look for a good butcher.