Creating Garlic Butter Roasted Onions is straightforward. Follow these simple steps for a delicious outcome:

1. Preheat Oven: Preheat your oven to 400°F (200°C).
2. Prepare Onions: Peel the onions and cut them into quarters or wedges, depending on your preference.
3. Melt Butter: In a small saucepan, melt the unsalted butter over low heat.
4. Add Garlic: Once the butter is melted, add minced garlic and sauté for about 1-2 minutes until fragrant. Be careful not to burn the garlic.
5. Season Onions: In a large bowl, combine the onion wedges with the melted garlic butter. Add salt, black pepper, and thyme (if using). Toss to coat evenly.
6. Arrange on Baking Sheet: Spread the seasoned onion wedges in a single layer on a baking sheet lined with parchment paper for easy cleanup.
7. Roast: Roast in the preheated oven for 30-35 minutes. Flip the onions halfway through cooking to ensure even caramelization.
8. Add Balsamic (optional): If using balsamic vinegar, drizzle it over the onions in the last 5 minutes of roasting for added depth of flavor.
9. Check for Doneness: The onions should be tender and caramelized when done. You can test this by inserting a fork; it should glide through easily.
10. Serve Warm: Remove from the oven and serve the Garlic Butter Roasted Onions warm.

These steps will guide you in creating Garlic Butter Roasted Onions that are bursting with flavor!