Heat a medium sized cast iron skillet (about 10 inches) over medium heat and add 4 Tablespoons (1/2 stick) unsalted butter.
Once melted, add 2 large yellow onions, thinly sliced, 1 Tablespoon Worcestershire sauce, 1 Tablespoon minced garlic, 1 teaspoon salt and 1 teaspoon black pepper.
Cook the onions, stirring occasionally, until deeply golden and caramelized, about 20-25 minutes. Reduce heat if they start to brown too quickly. Remove from heat and set aside to cool slightly.
Preheat the oven to 375F degrees.
Stir in 10.5 ounce can French Onion soup and 8 ounce block cream cheese, room temperature. Place skillet over low heat until cream cheese has completely melted.
Remove from heat and top with 12 ounce block gruyere cheese, shredded and 6 ounces French fried crispy onions.
Bake in the preheated oven for 20-25 minutes, or until the dip is bubbly and golden on top.
Garnish with fresh thyme Serve hot with 1 baguette, sliced.
Notes
Please refer to my FAQ’s (Frequently Asked Questions) and ingredient list above for other substitutions or for the answers to the most common questions.
If you don't have a heat safe skillet (like cast iron) transfer the prepared caramelized onion mixture to a 9x9-inch baking dish and continue with the recipe as written.