Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper for easy cleanup.
Dice the Yukon Gold potato into 1/2-inch cubes and toss in a bowl with 0.25 tbsp of olive oil, 0.25 tsp garlic powder, 0.25 tsp smoked paprika, and a pinch of sea salt and black pepper.
Spread the potatoes in a single layer on the prepared baking sheet and roast for 20-25 minutes, flipping halfway through, until they are golden and crispy.
While the potatoes roast, whisk together the remaining 0.25 tbsp olive oil, lemon juice, lemon zest, remaining garlic powder, smoked paprika, sea salt, and black pepper in a medium bowl.
Add the shrimp and chopped bell peppers to the marinade, tossing well to coat, and let sit for 10 minutes to absorb the flavors.
Heat a grill pan or outdoor grill over medium-high heat and cook the shrimp and peppers for 2-3 minutes per side until the shrimp are opaque and slightly charred.
Serve the zesty grilled shrimp and peppers immediately alongside the crispy roasted potatoes, garnishing with fresh parsley for a vibrant finish.