Step 1: Prepare the Ingredients

1. Pat the steak cubes dry with paper towels to remove excess moisture. This ensures a better sear. Season the steak generously with garlic powder, onion powder, salt, and black pepper.
2. If using fresh broccoli, cut it into bite-sized florets. If using frozen, let it thaw slightly and pat dry to prevent excess water in the skillet.

Step 2: Sear the Steak

1. Heat 1 tablespoon of olive oil in a large skillet over medium-high heat.
2. Once the oil is hot and shimmering, add the steak cubes in a single layer. Sear for 2-3 minutes on each side until the steak is browned and cooked to your desired doneness (135°F for medium-rare, 145°F for medium).
3. Remove the steak from the skillet and set it aside on a plate. Cover with foil to keep warm.

Step 3: Cook the Broccoli

1. In the same skillet, add the remaining 1 tablespoon of olive oil. Add the broccoli florets and season with a pinch of salt and pepper.
2. Sauté for 5-7 minutes, stirring occasionally, until the broccoli is bright green and tender-crisp. If needed, add a splash of water to steam the broccoli slightly.
3. Remove the broccoli from the skillet and set aside with the steak.

Step 4: Make the Lemon Garlic Sauce

1. Lower the heat to medium and add the butter to the skillet. Let it melt, then stir in the minced garlic and red pepper flakes (if using). Sauté for 30 seconds until fragrant.
2. Add the lemon juice, Dijon mustard, chicken broth, and lemon zest. Stir well and let the sauce simmer for 2-3 minutes, allowing it to thicken slightly. Taste and adjust seasoning if needed.

Step 5: Combine and Serve

1. Return the steak and broccoli to the skillet, tossing them gently in the lemon garlic sauce until everything is well coated and warmed through.
2. Garnish with fresh parsley and serve immediately.