Preheat your oven to 425°F and line a large baking sheet with parchment paper.
Slice the sweet potato into thin, even wedges and toss them in a bowl with the olive oil and half of the sea salt and black pepper.
Spread the sweet potato wedges in a single layer on the baking sheet and roast for 20-25 minutes, flipping halfway through, until edges are golden and crispy.
In a medium mixing bowl, combine the ground turkey, garlic powder, onion powder, and the remaining sea salt and black pepper.
Gently form the turkey mixture into one large, thick patty, being careful not to overwork the meat.
Heat a non-stick skillet over medium-high heat and sear the turkey patty for 5-6 minutes per side, or until the internal temperature reaches 165°F.
Wash and dry the romaine lettuce leaves to use as a sturdy wrap for the burger.
Place the cooked turkey patty inside the lettuce leaves and top with tomato slices and red onion.
Serve the warm turkey burger immediately alongside the hot sweet potato fries.