Place the potato slices in a bowl of cold water and soak for 45 minutes to remove excess starch.
Drain the potatoes and pat them very dry with paper towels or a clean kitchen towel (remove as much surface moisture as possible).
Pour vegetable oil into a deep pot or Dutch oven to a depth of about 2 inches and heat to 325°F (use a thermometer).
Working in small batches (do not overcrowd the pot), fry the potatoes at 325°F for 5–7 minutes, until the fries are soft through but not browned. Remove each batch with a slotted spoon or spider and drain on paper towels.
When all batches have been par-fried, increase the oil temperature to 360°F.
Fry the potatoes again in small batches at 360°F for 2–3 minutes, until they are golden and crispy. Drain on paper towels and season lightly with salt while hot.
Meanwhile, make the gravy: in a medium saucepan combine 1 cup low-sodium beef broth, 1 cup low-sodium chicken broth, 1/2 teaspoon onion powder, 3/4 teaspoon garlic powder, and 2 teaspoons Worcestershire sauce. Bring the mixture to a gentle simmer over medium heat.
In a small bowl, whisk together 3 tablespoons cornstarch and 5 tablespoons cold water until completely smooth to make a slurry.
With the broth simmering, slowly whisk in the cornstarch slurry a little at a time until the gravy reaches your desired thickness (you may not need to add it all at once). Continue to cook and whisk for about 2–3 minutes more until the gravy is glossy and thickened.
Taste the gravy and season with salt and pepper to taste; remove from heat.
To serve, arrange the hot fries on a plate or shallow dish, scatter 8 ounces room-temperature white cheddar cheese curds evenly over the fries, then pour the hot gravy over the top so the curds begin to soften and melt.