Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Dice the yellow potato into uniform 1/2-inch cubes and trim the woody ends off the asparagus spears.
Cut the chicken breast into bite-sized pieces, ensuring they are roughly the same size as the potato cubes for even cooking.
In a large mixing bowl, combine the potatoes, chicken, and asparagus, then toss thoroughly with the olive oil, minced garlic, rosemary, thyme, salt, and pepper.
Spread the mixture in a single, even layer on the prepared baking sheet, ensuring the ingredients are not overcrowded so they roast rather than steam.
Roast for 20-25 minutes, tossing the ingredients halfway through the cooking time, until the potatoes are golden-brown and the chicken is fully cooked.
Remove from the oven and immediately drizzle with fresh lemon juice and garnish with chopped parsley before serving.