To make the onion spread: Drizzle the vegetable oil into a wide pan over high heat. Once hot, add the onion rings and saute for about 2 to 3 minutes. Then, reduce the heat to low, and cook slowly for 30 minutes, stirring occasionally. When the rings are nice, soft and a medium-golden brown color, pull them off the heat.
Season with the kosher salt, black pepper and smoked paprika.
Put the softened and malleable cream cheese into a bowl. Incorporate the caramelized onions and stir with a spatula to combine. The heat of the onions will help melt the cheese.
The leftovers can be saved, refrigerated, in an airtight container for about a week and used on bread, burgers, or almost anything.
To make the blue cheese spread: Place the softened cream cheese into a bowl with the crumbled blue cheese. Using a spatula, mix the cheeses together until they develop a nice and smooth consistency, adding a drizzle of heavy cream if the mixture is too stiff.
Season the mixture with the Worcestershire, chives, salt and black pepper.
To make the stuffed celery: Place both spreads into 2 separate heavy plastic bags. Cut off the tip of 1 corner from each bag and use them to pipe the spreads onto the celery stalks.