Caramelized Onion, Gruyère, and Bacon Spread

Serve this savory caramelized onion, gruyere and bacon spread on crackers or slices of bread. If you can't find Gruyere, replace it with raclette, fontina, or Swiss cheese.
Preheat the oven to 425 degrees.Heat a large cast-iron skillet over medium-high heat. Lightly brush the mold with cooking spray. Add the onion to the pan; simmer for 5 minutes, stirring frequently. Reduce heat to low; cook for 20 minutes or until golden brown, stirring occasionally. Allow to cool slightly.Leave 2 tablespoons of cheese. Combine the remaining cheese, caramelized onion, 1 tablespoon green onion, and remaining ingredients in a medium bowl. Transfer the mixture to a 1-liter glass or ceramic baking dish lightly greased with cooking spray. Sprinkle with the remaining 2 tablespoons of cheese. Bake at 425 ° C for 20 minutes or until lightly browned and bubbling. Sprinkle with the remaining 1 tablespoon green onion.