Preheat your oven to 400°F.
Peel and cube the sweet potato and Yukon gold potato, then boil them in a pot of water until tender, approximately 12 minutes.
Drain the potatoes and mash them together until smooth, adding a splash of broth if needed for creaminess.
While potatoes boil, heat the olive oil in a large skillet over medium heat.
Add the diced chicken breast and ground beef to the skillet, browning the meat thoroughly.
Stir in the diced carrots and minced garlic, cooking for 5 minutes until the carrots begin to soften.
Add the frozen peas, sea salt, black pepper, dried thyme, and beef broth to the skillet, simmering for 3 minutes until the liquid reduces slightly.
Transfer the meat and vegetable mixture into a small oven-safe baking dish.
Spread the mashed potato mixture evenly over the top of the meat, using a fork to create decorative ridges.
Bake for 15 minutes until the potato topping is lightly golden and the edges are bubbling.