Fill a large Dutch oven with 2 inches of canola oil and heat to 350 degrees F, or prepare a countertop deep-fryer according to manufacturer's directions. Slice the potatoes into 1/4-inch-thick rounds. Set aside.
Meanwhile, make the gravy. Put the bacon in a large skillet over medium heat and cook until crispy and most of the fat has been rendered, stirring occasionally, 20 to 25 minutes. Transfer to a paper towel-lined plate to absorb any excess fat and reserve. Remove all but 3 tablespoons of the fat from the skillet.
Add the onions and cook over medium heat until softened, 3 to 5 minutes. Stir in 1/4 cup of the beef stock to combine, and then stir in the flour to combine and cook, stirring, until light brown and thickened, 2 to 3 minutes. Add the remaining stock and bring to a boil over medium-high heat, and then reduce to a simmer and cook, stirring frequently, until the sauce is thickened to the consistency of gravy, 6 to 8 minutes. Season with salt and pepper. Turn off the heat, cover with a lid and set aside.
Fry the potatoes in batches until cooked through but still pale in color, flipping occasionally with a slotted spoon, 3 to 4 minutes. Remove using the slotted spoon and transfer to a paper towel-lined baking sheet to absorb excess oil.
When all of the potatoes have been fried, increase the heat to 375 degrees F. Fry the potatoes in batches until they are golden brown and crispy, flipping occasionally, 2 to 3 minutes. Wait for the oil to come back up to 375 degrees F before frying another batch. Remove using the slotted spoon and transfer to a paper towel-lined baking sheet to absorb excess oil. Season lightly with salt.
Preheat the broiler and place a rack on the second-to-top position of the oven.
Spread out the crispy potatoes on a large baking sheet in a slightly overlapping single layer. Drizzle all over with half of the warm gravy. Evenly scatter the cheese curds and reserved bacon over the top. Place under the broiler until the curds are lightly browned and beginning to melt, 2 to 3 minutes. Transfer the poutine to a large platter or serve directly on the warm baking sheet. Garnish with the chives and serve with the remaining warm gravy on the side.
NotesCook's Note: Starting the bacon in a cold pan over medium heat allows you to cook the bacon slower, resulting in maximum rendering and crispness.