Pat the sirloin steak and shrimp dry with a paper towel and season both with the sea salt and black pepper.
Heat a large cast-iron skillet or wok over medium-high heat with half of the avocado oil.
Add the steak cubes to the hot pan in a single layer, searing for 2-3 minutes until browned on all sides, then remove and set aside.
In the same pan, add the shrimp and cook for 1-2 minutes per side until they are pink and opaque, then remove and set aside.
Add the remaining oil to the pan along with the zucchini, onions, and mushrooms, sautéing for 4-5 minutes until the vegetables are tender-crisp.
Stir in the minced garlic and ginger, cooking for 30 seconds until fragrant.
Return the steak and shrimp to the pan, pour in the coconut aminos, and toss everything together for 1 minute to allow the sauce to glaze the ingredients.
Garnish with sesame seeds and serve immediately while steaming hot.