Cut roast down center lengthwise within a half-inch of bottom. Open roast so it lies flat.
On each half, make a lengthwise slit down the center to within a half-inch of bottom. Sprinkle with salt, garlic and pepper.
In a large bowl, combine remaining ingredients. Divide half the stuffing among the 3 slits.
Roll up roast from a long side; tie with kitchen string at 2-inch intervals.
Place remaining stuffing in a greased shallow baking dish.
Bake roast uncovered in preheated 350-degree F oven for 1½ to 2 hours. Carefully remove strings; cover lightly with foil tent and bake 30 to 45 minutes longer or until thermometer reads 160 to 170 degrees.
Cover and bake reserved stuffing for approximately 30 minutes.