the polenta until it is lightly crispy and marked with the characteristic brown stripes on both sides. To broil set the polenta on a broiler pan about 4" from the heat and broil turning once until the slices are golden and slightly crisp at the edges. Remove and set on a platter. While the polenta is broiling discard any bruised outside leaves of the radicchio cut it in half lengthwise and then cut into quarters. Wash and dry each piece carefully. Drizzle half the olive oil over the radicchio and season with salt and pepper. Set on an oiled broiler or on the barbecue. As the radicchio begins to soften and darken in color turn it to broil evenly. Using your fingers or a knife tear or cut the grilled radicchio into small pieces. Arrange over the polenta and drizzle with the rest of the olive oil and vinegar if you desire. Taste for salt. Add freshly ground pepper and serve hot or at room temperature.