Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
Cut the potato into thin, even matchsticks to ensure uniform cooking.
Toss the potato strips with olive oil and half of the salt and pepper, then spread them in a single layer on the baking sheet.
Bake the fries for 20-25 minutes, flipping halfway through, until they are golden and crispy.
While the fries bake, combine the ground beef with the garlic powder and the remaining salt and pepper in a bowl.
Form the beef into a single thick patty, making a small indentation in the center with your thumb to prevent bulging.
Heat a non-stick skillet over medium-high heat and sear the patty for 4-5 minutes per side until cooked to your desired doneness.
Lightly toast the whole wheat bun in the skillet or oven for 1-2 minutes.
Assemble the burger by placing the beef patty on the bottom bun, followed by the lettuce, tomato, and red onion.
Serve the hot burger immediately alongside the crispy golden fries.