1. Place a rack in lower-middle of oven and heat to 450 degrees.
2. Cut sweet potatoes into 1/4"-thick fries, then transfer to a parchment-lined baking sheet. Add 1 tablespoon oil and the ranch seasoning and toss to coat. Transfer to oven and bake until golden brown, about 25 minutes, flipping halfway through.
3. Meanwhile, place chicken between two pieces of parchment and use a skillet or rolling pin to flatten to a 1/2" thickness; season with salt and pepper.
4. Heat remaining 1 tablespoon oil in a large oven-safe skillet over medium-high. Add chicken and cook until golden brown, about 3 minutes per side, then add cheese and cover. Reduce heat to medium-low and cook until cheese is melted and centers of chicken register 165 degrees, 2 to 4 more minutes. Transfer to a plate and cover to keep warm.
5. Add mushrooms, onion, and stock to skillet and cook over medium heat until mushrooms are tender and liquid has mostly evaporated, 8 to 10 minutes. Add marinade and cook, stirring occasionally, until mixture is lightly caramelized, 2 to 3 minutes; season with salt and pepper to taste. Divide chicken and mushrooms among buns and serve with fries.
Source: Hannaford fresh Magazine, December 2020