Heat the oven to 400 degrees
In a small bowl combine the radishes, oil and salt. Evenly distribute on a foil-lined baking sheet. Roast for 10 minutes, until tender. Remove from the oven. Increase the heat to 500 degrees.
Meanwhile, cook the sausage until slightly underdone.
Roll out the pizza dough. Place a layer of tomato sauce on the dough. Next add a handful of cheese to cover the sauce. Add the sausage, radishes and shallots to the pizza. Top with a sprinkling of cheese. Place in the oven and cook until the dough is golden and the cheese melted and browned, about 8-15 minutes.