Melt butter over medium heat in a medium saucepan. Add sliced onions with a pinch of salt and stir often. Cook for about 15 minutes until golden brown and caramelized.

Add the rice and stir to coat it in butter. Toast for about 2-3 minutes until it has a nutty aroma.

Pour in beef broth, garlic powder, and thyme. Stir and bring to a boil.

Reduce heat to low, cover, and let simmer for 18-20 minutes until rice is tender and liquid is absorbed.

Remove from heat and fluff rice with a fork. Stir in Parmesan cheese if desired. Season with salt and pepper to taste. Garnish with fresh parsley before serving.