Heat oil or butter in non stick skillet over medium heat. Once hot, add the onion and sauté until it begins to get translucent, about 2-3 minutes. Add in the frozen cauliflower rice, garlic and thyme (if using), and sauté about 30 seconds until garlic is fragrant. Add in the broth, lower the heat to a simmer, and stir fry the cauliflower about 10 minutes, until the liquid is absorbed, the cauliflower is tender, and about 1/3 of the rice bits have started to brown.