Although I also like lamb roasted with rosemary and garlic, a plain roast with mint sauce is something special.
In the land of Oz, we have mint sauce (vinegar based with loads of mint), mint jelly (a loose gelatin based condiment that melts into the warm lamb on your plate) and there is also “lamb jam”, a firmer mint based jelly that melts a bit but still remains separate. All three work with roast and chops - mmmmm bbq lamb chops. There are small differences between brands but not a great deal.