Step 1

To get started, gather your ingredients. Slice the onion thinly, about a quarter-inch thick. This thickness ensures they cook evenly without burning.

Step 2

Heat a large skillet over medium heat, and then add in the butter. Let it melt completely, covering the base of the skillet with its rich, golden goodness.

Step 3

Once the butter is hot, toss the sliced onions into the skillet. Use a spatula to stir the onions so they coat themselves in the melted butter. This is key to achieving that delightful caramelization.

Step 4

Sprinkle the sea salt and brown sugar over the onions. The sugar not only adds sweetness but helps them caramelize faster. Stir gently to distribute the seasoning evenly.

Step 5

Now, let the magic happen. Cook the onions for about 15-20 minutes, stirring occasionally. If you notice them browning too quickly, lower the heat. You want them to turn a deep golden brown, not burn.

Step 6

If the onions begin to stick to the pan, add a splash of water. This helps in loosening them while continuing to cook.

Step 7

After about 20 minutes, you should have beautifully caramelized onions. If using, toss in a sprig of fresh thyme during the last minute of cooking to incorporate herby notes.

Step 8

Once your grilled onions are perfectly done, remove them from the heat. They’re ready to top off your burgers, or you can serve them as a side. Their flavor will shine through every dish you prepare.