Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Slice the baby potatoes into halves and toss them on the baking sheet with half of the olive oil and a pinch of sea salt.
Roast the potatoes for 22-25 minutes, flipping halfway through, until they are golden brown and crispy on the edges.
While potatoes roast, season the chicken breast on both sides with dried oregano, garlic powder, sea salt, and black pepper.
Heat the remaining olive oil in a medium non-stick skillet over medium-high heat.
Add the chicken to the skillet and sear for 6 to 7 minutes per side, or until the internal temperature reaches 165°F.
In a small mixing bowl, whisk together the fresh lemon juice and lemon zest to create a bright dressing.
Place the arugula in a salad bowl and toss with half of the lemon dressing until lightly coated.
Remove the chicken from the pan and let it rest for 3 minutes before slicing into thick strips.
Plate the sliced chicken alongside the roasted potatoes and arugula salad, drizzling the remaining lemon dressing over the chicken before serving.