Sumac is elaborately hand-processed from the ground ripe berries of a tree (rhus coriaria) native to eastern Europe. It has a lovely tangy fruitiness and a scent similar to freshly-cut apple. Sprinkled on before and/or after cooking, sumac is delicious with roasted or grilled fish, poultry or meat, particularly roast lamb. The wonderful fruity tartness of sumac also beautifully complements salads, tomatoes, sweet onions and avocados and beans. The best quality sumac is deep red and slightly moist and soft.