Pour the stock into a pan and bring to a boil, then reduce the heat and simmer. Meanwhile, melt the butter and olive oil in another pan. Add the garlic, onion thyme and cook over low heat, stirring occasionally, for 5 minutes, or until it is softened. Add the rice and cook, stirring, until all the grains are coated with melted butter. Add the wine and cook to evaporate for 4 minutes. Add a ladleful of the hot stock to the rice and cook, stirring, until it has been absorbed. Continue adding the stock, a ladleful at a time, and stirring until each addition has been absorbed. This will take 18-20 minutes. Meanwhile, set a few whole strawberries aside for the garnish and mash the remainder in a bowl. Ten minutes before the end of the cooking time, add the mashed strawberries to the risotto. When it is almost ready, gently stir in the cream and Parmesan and season with salt and pepper. Serve garnished with the reserved whole strawberries.