Mutton has a slightly "gamey" flavor, is there a way to prep it before cooking which reduces this "gamey" flavour?
The flavor will vary greatly depending on the cut of meat and the preparation.
- Different cuts (eg: chops and legs) taste very differently from one another (legs and tougher meat taste more gamey)
- Ground lamb has almost no gamey flavor
- Well done meat will taste less gamey than medium (Edit: regarding "done-ness" this how it tastes to me. Since answering, I've discussed this with someone else who says the opposite is their experience)
- Cooking with a lot of vegetables or a flavorful starch will by contrast cut down on the strong flavor more than a bland starch. A bland starch will result in highlighting the strong gamey taste
Most of the gamey-ness comes from the fat. Unlike the pork or beef fat, mutton fat has a strong odor and is considered to be inedible by most people. You want to trim off as much of it as possible. http://chestofbooks.com/health/nutrition/Medicinal-Meals/Mutton-Fat.html
It also depends on whether the goat was grain-fed or grass-fed. The latter, although more natural, tend to produce meat that has a strong smell.
As for cooking mutton, I've found the only satisfactory way of getting rid of the smell is to make a curry out of it. There are many good Indian mutton curry recipes on the web.
Are you talking about lamb in general or mutton?
Mutton does have a strong flavour - this can be reduced by removing the pink skin and trimming off superfluous fat.
You can also complement the flavour by adding things like garlic, olive oil, mint, wine, rosemary and thyme, pepper, dry mustard and curry powder.