Preheat oven to 375 degrees F.
Add chicken stock and salt to a medium sized pot and bring to a boil. Reduce heat to simmer.
Whisk instant polenta into stock and stir constantly for 3 to 4 minutes. Remove from heat and add in butter and olive oil. Check seasonings. Pour polenta into a low rectangular buttered dish so it is approximately 1 inch thick. Cool for at least 1 hour. Cut into 2 inch squares.
Heat olive oil in a sauté pan. Brown each square of polenta on both sides. Transfer to a baking dish and bake in oven for 5 to 10 minutes.
Place approximately 3 tablespoons of Gorgonzola cheese on the top of each square allowing it to melt.
Preheat grill to high.
Cut radicchio di Treviso into quarters. Combine olive oil and garlic and drizzle over radicchio quarters. Season. Grill until radicchio is slightly wilted. Set aside.
On a plate, place 1 square of polenta and decoratively arrange 2 wedges of tomato and one piece of the grilled radicchio di Treviso. Sprinkle entire dish with olive oil, balsamic vinegar and freshly cracked black pepper.