Preheat your oven to 400°F and line a large sheet pan with parchment paper to ensure even roasting without sticking.
Wash and dice the Yukon gold potatoes into small 1/2-inch cubes, keeping the skins on for extra fiber and texture.
In a small bowl, whisk together the olive oil, garlic powder, dried rosemary, sea salt, and black pepper.
Toss the potato cubes with half of the herb oil mixture and spread them in a single layer on the prepared baking sheet.
Roast the potatoes for 12 minutes to give them a head start on becoming perfectly golden and tender.
While potatoes roast, coat the chicken tenderloins and broccoli florets with the remaining herb oil mixture.
Remove the pan from the oven, slide the potatoes to one side, and add the chicken and broccoli to the empty space.
Return the pan to the oven and roast for an additional 12-15 minutes until the chicken is cooked through and the broccoli is tender-crisp.
Drizzle the fresh lemon juice over the chicken and broccoli just before serving to brighten all the savory flavors.