In a large skillet, melt 2 tablespoons of unsalted butter over medium heat until it becomes foamy. Add in thinly sliced yellow onions along with a pinch of salt, stirring to incorporate. Sauté for 25-30 minutes until golden brown and caramelized, stirring occasionally.

Stir in 2 minced garlic cloves and sauté for an additional 1-2 minutes until fragrant.

Add 1 cup of Arborio rice into the skillet, stirring to coat well. Allow to cook for about 2 minutes.

Pour in 4 cups of low-sodium chicken broth, stirring to combine. Bring to a boil, then reduce to low heat, cover, and let simmer for 15-20 minutes until the rice is tender.

Remove from heat, stir in 1/2 cup of grated Parmesan cheese and freshly chopped thyme until well combined.

If the rice seems too thick, adjust the consistency by adding extra broth. Serve warm.