Melt butter in a medium-size saucepan; add the onion and ½ teaspoon salt. Cook the onion in the butter until just softened. Add the rice and continue cooking until the rice starts to turn translucent. Mix in the garlic and thyme and continue cooking until fragrant – about 30 seconds.
Add the bay leaf and then mix broth into the rice mixture, bring to a boil, reduce heat to low, cover and cook for 20 minutes or until liquid is absorbed and rice is tender.