Preheat the oven to 400. Heat a medium pot of salted water to boiling on high. Peel and cube the sweet potatoes, thinly slice the red onion, pick the sage leaves off the stems, and halve the brussel sprouts.
Add the sweet potatoes to the pot of boiling water. Cook 9 to 11 minutes, or until very tender when pierced with a fork. Drain and transfer to a bowl. Spread the brussel sprouts and red onion evenly on a rimmed baking sheet, drizzle with olive oil, and season with salt and pepper. Roast for 20 to 30 minutes or until crispy and drizzle with balsamic glaze.
Heat a grilled pan over medium heat and spray with cooking spray. Lightly pat dry the pork chops to remove excess moisture and season with salt and pepper. Add the pork to the pan for 4 to 5 minutes on each side. Allow the pork to rest for 5 to 8 minutes.
Add the butter and brown sugar to the bowl with the sweet potatoes. Using a fork, mash everything together until combined. Season with salt and pepper. Stack and roll the sage leaves and thinly slice them.
Plate the pork chops, balsamic brussel sprouts, and mashed sweet potatoes. Sprinkle the sage over the top of the sweet potatoes and serve with a lemon wedge.