Preheat the Oven: Preheat your oven to 375°F (190°C).

Season the Chicken: In a small bowl, mix together the garlic powder, dried thyme, paprika, salt, and pepper. Massage the chicken breasts with olive oil, ensuring they are thoroughly covered with the seasoning blend.

Sear the Chicken: Heat a large oven-safe skillet or casserole dish over medium-high heat. Add a drizzle of olive oil, then sear the chicken breasts on both sides until golden brown, about 3-4 minutes per side.

Prepare the Vegetables: In the same skillet, add the diced onion and cook for 2-3 minutes until softened. Add the sliced carrots, asparagus, and sugar snap peas. Sauté the vegetables for another 2-3 minutes, just until they begin to soften.

Assemble the Casserole: Pour the chicken broth over the sautéed vegetables, stirring to combine. Place the seared chicken breasts on top of the vegetables in the skillet or casserole dish.

Bake the Casserole: Cover the dish with foil and transfer it to the preheated oven. Bake for 20-25 minutes, or until the chicken is fully cooked and reaches an internal temperature of 165°F (75°C).

Add the Cheese: Remove the casserole from the oven, uncover, and sprinkle the shredded cheese evenly over the chicken and vegetables. Return the dish to the oven, uncovered, and bake for an additional 5 minutes, or until the cheese is melted and bubbly.

Garnish and Serve: Once the cheese is fully melted, remove the casserole from the oven and let it rest for 5 minutes. Garnish with fresh parsley if desired, and serve hot.