Preheat oven to 425°F.
Cut the top tip of each head garlic off, just enough to expose all of the cloves. Place each head on a separate piece of tin foil. Drizzle with olive oil and seal the foil around the garlic.
Place both garlic packets on a baking sheet or baking dish. Roast in the oven for 30 minutes. Remove from oven and allow to cool.
Reduce oven temp to 350°F.
In a food processor add the cream cheese, 1 1/2 cup Reggiano, gouda, beer, red chili sauce, salt, pepper, and cornstarch. Squeeze the roasted heads of garlic until the soft cloves come out, add the roasted cloves to the food processor, taking care that none of the papery garlic skin is added to the food processor. Discard the empty garlic head. Process until well combined.
Add to a baking dish, top with the remaining 1/4 cup cheese.
Bake until melted and the top has started to turn a light golden brown, about 35-40 minutes. Remove from oven, stir (it will have puffed slightly) top with green onions, serve warm.