Melt the butter with the olive oil over medium low heat in a large skillet or saucepan. Add the diced onion to the pan and drop the heat to LOW, stirring frequently until the onions are translucent but not browned. This should take about 8 to 10 minutes. Add the garlic to the onions and stir until fragrant. Stir in the rice with a wooden spoon until toasted and opaque, 3 to 4 minutes.

Add the wine to the pan, and let it bubble up and absorb. Add the thyme, and start adding the stock - 1/2 cup at a time- and cook, stirring, until it is absorbed. Continue adding the stock 1/2 cup at a time, waiting until the liquid is almost entirely absorbed before adding more. Cook until the rice is tender and creamy but still a little al dente, about 15 to 20 minutes. Add the cheese to the rice and mix well until melted. Serve hot or warm, topped or naked as desired.