1. Preheat the oven to 500°. If you have a pizza stone, place it in the oven while it preheats. In a large skillet set over high heat, add ¼ cup of the olive oil and the mushrooms. Cook the mushrooms, tossing often, until the water that is released from them evaporates and the mushrooms begin to brown, about 7 to 10 minutes. Add the thyme and half of the garlic and cook for 30 seconds, stirring constantly. Add the lemon juice and season with salt and pepper. Remove the pan from the heat and set aside.

2. In another large skillet set over medium heat, warm the remaining 2 tablespoons of olive oil. Add the remaining garlic and stir until the garlic turns golden, about 30 seconds. Add the radicchio, leek and rosemary and season with salt and pepper. Cook, stirring occasionally, until the vegetables are wilted, about 8 to 10 minutes. Remove the pan from the heat and set aside.

3. On a floured board, stretch and roll each half of the pizza dough into a 12-inch round. Place one of the rounds on a floured pizza peel or pan. Place half of the Taleggio on the round. Scatter half of the mushrooms and half of the radicchio-leek mixture evenly over the pizza, slide onto the preheated stone and bake until crisp and golden, about 8 to 10 minutes. Repeat with the second half of pizza dough. Serve hot.