Pat the sirloin steak and shrimp completely dry with paper towels to ensure a high-quality sear.
Cut the steak into 1-inch cubes and season both the steak and shrimp with sea salt and black pepper.
Heat a large cast-iron skillet or griddle over high heat and add the avocado oil once the pan is shimmering.
Place the steak cubes in the pan in a single layer, searing for 2 minutes until a brown crust forms, then remove and set aside.
Add the shrimp to the pan and cook for 1 to 2 minutes per side until pink and opaque, then remove and set aside.
Lower the heat slightly to medium-high, add the ghee to the pan, and toss in the sliced zucchini, onions, and mushrooms.
Sauté the vegetables for 4 to 5 minutes until they are tender but still retain a crisp bite.
Stir in the minced garlic and grated ginger, cooking for 30 seconds until the aromatics are fragrant.
Return the steak and shrimp to the pan, drizzle with coconut aminos, and toss everything together for 1 minute to glaze.
Garnish the dish with sesame seeds and serve immediately while hot.