1 1/2 kg leg of lamb butterflied
1/3 cup of olive oil
1/2 cup lemon juice
2 tablespoons red wine vinegar
2 cloves garlic, crushed
2 tablespoons chopped fresh flat leaved parsley
1 teaspoon dried oregano leaves

Mix ingredients and marinate lamb for 24 hrs

Now, Ivan's touch...  ;-)

Quadruple the marinade quantities and triple the marinating time - nothing like overdoing it, and it works great.