Heat a medium stockpot over medium heat and add olive oil and butter. Add onions and garlic and cook until soft and translucent.
Add rice and stir to coat the rice thoroughly with the oil and butter. Add 1 cup of broth, simmering and stirring constantly until absorbed. When rice absorbs the liquid, stir in additional broth 1 cup at a time. The broth should simmer gently. If it boils too hard or the rice is sticking to the pan, reduce the heat slightly. Continue stirring and adding broth in 1-cup increments until all the broth is used. The rice is done when it is soft and creamy, and no longer has a hard bite.
Add Parmesan cheese and stir until cheese is melted and risotto is creamy. Stir in spinach, basil, and thyme leaves until wilted. Season with Black Truffle Salt and black pepper to taste.