In a large Dutch oven, heat 2 tablespoons of butter and a tablespoon of olive oil over medium-high heat. Add 4 thinly sliced sweet onions, 2 teaspoons of fresh thyme, 2 bay leaves, and a pinch of salt and pepper. Stir frequently for about 10 minutes until the onions begin to soften and turn translucent.

Reduce the heat to medium-low and continue to cook the onions for 40-45 minutes, stirring occasionally until they turn deep golden brown.

Add 1/2 cup of sherry wine and 1 cup of beef stock to the pot. Cook for an additional 6-8 minutes until the liquid reduces and coats the onions lightly.

Preheat your oven to 550°F. If you have a pizza stone, place it in the oven to heat.

Roll out your pizza dough on a floured surface to a 10-inch circle and transfer to a prepared baking sheet or pizza peel.

Brush the dough generously with olive oil. Sprinkle a layer of Gruyere and mozzarella cheese evenly over it.

Spoon the cooled caramelized onion mixture over the cheese layer.

Slide the pizza onto the preheated stone or place the baking sheet in the oven. Bake for 10-12 minutes.

Let the pizza cool for a minute, slice into wedges, and serve immediately.