In a small bowl or measuring cup, whisk together the coconut aminos, chicken broth, toasted sesame oil, rice vinegar or lime juice, minced garlic, sriracha (if using), grated ginger, and tapioca flour or cornstarch until smooth.
Season the sauce with 1/2 teaspoon sea salt and 1/4 teaspoon black pepper, adjusting to taste; set the sauce aside.
Heat a 12-inch skillet over medium-high heat and add 1 tablespoon avocado oil.
Add the cubed ribeye to the hot skillet in a single layer and sear without moving for 3–4 minutes to develop a good crust.
Add the broccoli florets to the skillet, pour the prepared sauce over the beef and broccoli, and bring the mixture to a full boil.
Cook, stirring occasionally, until the broccoli is tender to your liking and the sauce has thickened, about 2–4 minutes.
Taste and adjust seasoning with additional sea salt and black pepper if desired, then serve the beef and broccoli over the Coconut Lime Rice.
Optional: sprinkle with sesame seeds before serving.