Preheat oven to 375°F. Spray a 2-quart shallow baking dish with cooking spray.
Using a hand mixer, combine cream cheese and Boursin cheese. Mix until incorporated and creamy.
16 ounces cream cheese, 5.2 ounces Boursin cheese
Add in grated Parmesan, Gruyere, and onion. Mix together well.
¾ cup freshly grated Parmesan cheese, ¼ cup freshly shredded Gruyere cheese, 2 cups diced sweet yellow onion
Pour the mixture into the prepared dish, and bake in the preheated oven for 45-60 minutes, or until the top is golden brown.
Remove from oven – let cool 10 minutes then serve with favorite crackers, chips and/or vegetables.