Heat the chicken broth in a saucepan over medium heat until just simmering. Remove from the heat and set aside for a few minutes. Over medium heat in a medium-sized saucepot, heat the olive oil until shimmering and add the onion and salt. Cook until the onion has softened through, about three minutes. Add the rice and stir to combine. Cook, stirring often, until the rice has started to cook through. You’ll know it’s ready when the ends of the grains are starting to turn clear, and the center of each grain is still white.
Add the white wine and deglaze the pan. Cook off the alcohol, about two to three minutes. Add the chicken stock ¼ cup at a time, stirring often and waiting until the liquid is mostly absorbed between each addition. When all of the chicken stock has been added continue to cook and stir until the risotto is creamy but not sticky or overly liquidy.
Add the parmesan, thyme and lemon and stir to combine. Season to taste with salt and freshly cracked pepper, if desired.