Preheat the oven to 425 degrees F and line a large sheet pan with parchment paper.
In a large bowl, stir together the olive oil, minced garlic, lemon zest, lemon juice, oregano, salt, and pepper.
Add the halved potatoes and chicken thighs to the bowl. Toss until everything is evenly coated.
Spread the potatoes and chicken in a single layer on the prepared sheet pan. Place the pan in the oven and roast for 15 minutes.
Remove the pan from the oven. Add the asparagus to the pan and toss lightly with the existing juices. Return the pan to the oven and roast for another 10 to 12 minutes until the chicken reaches 165 degrees F and the potatoes are tender.
Sprinkle the chopped parsley over the finished dish before serving.