PREHEAT OVEN TO 375 DEGREES.PLACE THE CHICKEN ON IT'S BREAST ON A FLAT WORK SURFACE.USING POULTRY SHEARS,CUT ALONG THE ENTIRE LENGTH OF THE BACKBONE.SPREAD THE CHICKEN OPEN AND RINSE WITH COLD WATER.DRY WITH PAPER TOWELS.CUT OFF EXCESS FAT AT NECK AND TAIL,AND DISCARD FAT. OPEN THE BIRD OUT AS MUCH AS POSSIBLE.USE THE HEEL OF YOUR HAND AND STRIKE THE BREAST FIRMLY TO BREAK THE BREAST BONE,COLLAR BONES,RIB CAGE,AN WISHBONE.PLACE THE PARSLEY,CELERY,ONION INTO A 10 TO 30 cm OVEN PROOF SKILLET OR BAKING DISH,AND LAY THE CHICKEN,BREAST SIDE UP,ON TOP,ARRANGING THE BIRD SO IT RESTS NEATLY IN THE SKILLET.SPRINKLE CHICKEN WITH SAlt,AND PEPPER AND PAPRIKA,AND DOT WITH BUTTER. ROAST UNCOVERED FOR 35 MINUTES OR UNTIL CHICKEN HAS BEGUN TO BROWN.IN A TWO CUP MEASURING CUP,COMBINE BROTH,LEMON JUICE,AND WINE.RESERVE quarter CUP O THE LIQUID,AND ADD THE REST TO THE SKILLET.BASTE THE CHICKEN,AND CONTINUE ROAST UNCOVERED,BASTING EVERY 15 MINUTES,FOR 50 TO 60 MINUTES LONGER,OR UNTIL THE SKIN IS A DEEP GOLDEN BROWN AND JUICES RUN CLEAR WHEN CHICKEN IS PIERCED IN THE THIICKEST PART OF THE THIGH AND INTERAL TEMPERATURE REGISTE 180 DEGREES. TRANSFER CHICKEN TO A WARM PLATTER OR GROOVED CARVIONG BOARD AND KEEP WARM BY COVERING WITH A TENT OF FOIL.DISCARD THE VEGETABLES.TILT THE SKILLET,AND SPOON OFF THE FAT.STRAIN THE DEFATTED COOKING JUICES IF DESIRE AND RETURN JUICES TO THE SKILLET. STIR CORNSTARCH INTO THE RESERVED quarter CUP BROTH WINE MIXTURE.ADD THE DISSOLVED CORNSTARCH MIXTURE TO THE BROTH IN THE SKILLET.BRINNG TO A SIMMER,AND STIR FREQUENTLY UNTIL THHICKENED.SERVE GRAVY ALONG SIDE CHICKEN....................