• 3 Tbsp butter
• 8 oz Fontina cheese, grated
• 1 Tbsp fresh thyme, chopped
• 1 Tbsp granulated sugar
• ½ tsp salt and pepper, to taste
• 1½ Tbsp Worcestershire sauce
• 3 yellow onions, halved and sliced thinly
• 3 zucchini, spiralized
• ½ to ¾ cup low-sodium beef broth

Preheat oven to 400 degrees F. Mist a casserole dish with non-stick cooking spray; set aside.Melt butter in a large skillet over medium heat. Once hot and bubbly, add sliced onion and sprinkle with salt, pepper, sugar, thyme, and Worcestershire sauce. Stir and cook for 2-3 minutes. Add cup beef broth, stir, and cook until onions are golden brown about 20 minutes, stirring just a few times and adding additional beef broth, if needed.In a large bowl combine zucchini noodles and onion mixture; transfer to the prepared casserole dish and top with cheese.Bake for 20 to 25 minutes or until golden brown. Remove from oven and allow to cool for 2-3 minutes before serving.