JUST BEFORE THEIR LEAVES TURN THE COUNTRYSIDE A PIERCING SHADE OF BURNT ORANGE, THE CHESTNUT TREES IN SPAIN RELEASE THEIR NUTS. FROM INSIDE A COARSE PRICKLY CASE COME A FEW SHINY CHESTNUTS, THE LAST REAL CROP OF ABUNDANCE BEFORE WINTER. WALK THE STREETS OF SPAIN WHEN THE AIR BEGINS TO CHILL AND THERE IS A CONSTANT FRAGRANT NOTE — THE AROMA OF CHESTNUTS ROASTING. FAST STREET FOOD IS FUN, BUT CHESTNUTS ARE SERIOUS BUSINESS IN SPAIN. PRIOR TO THE ARRIVAL OF POTATOES THEY WERE THE MAIN SOURCE OF WINTER STARCH, AND TO THIS DAY THE EXTRAMENANS AND GALICIANS STILL MAKE A SOUP OF CHESTNUTS AND PORK. PRESERVING CHESTNUTS IN SUGAR IS A WAY OF KEEPING THEM OVER THE WINTER. THIS RECIPE CREATES A LOVELY AROMATIC SYRUP THAT CAN BE SERVED WITH THE CHESTNUTS WITH CREPES (SEE RECIPE), WITH ICE CREAM OR STEWED FRUIT.