Heat a large cast-iron skillet over medium-high heat until it is screaming hot, then add the ghee to coat the surface.
Pat the steak and shrimp dry with a paper towel to ensure a perfect crust, then season evenly with garlic powder, sea salt, and black pepper.
Place the steak cubes in a single layer on one side of the skillet, searing undisturbed for 2 minutes before flipping to develop a golden-brown crust.
Add the shrimp to the other side, cooking for about 90 seconds per side until they turn pink and curl slightly into a C shape.
Transfer the proteins to a clean plate to rest, keeping the flavorful drippings in the pan for the vegetables.
Toss the sliced onion, zucchini, and carrots into the skillet, sautéing for 4 minutes until they are tender but still have a vibrant snap.
Deglaze the pan by stirring in the cooked brown rice, coconut aminos, and toasted sesame oil, scraping up any browned bits from the bottom.
Fold the steak and shrimp back into the vegetable and rice mixture, tossing for 1 minute to marry the flavors before serving hot.