Step 1: Roast the Garlic Broccoli : Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper. Toss broccoli florets with olive oil, garlic, salt, pepper, and chili flakes. Spread evenly on the baking sheet and roast for 15–18 minutes, stirring once halfway, until tender and slightly crisp on the edges. Sprinkle Parmesan before serving, if desired.
Step 2: Prepare the Salmon : Pat salmon fillets dry with paper towels and season both sides with salt and black pepper. Heat olive oil in a large skillet over medium-high heat. Place salmon skin-side down (if applicable) and sear for 3–4 minutes per side until golden and nearly cooked through. Transfer salmon to a plate and keep warm.
Step 3: Make the Lemon Butter Sauce : In the same skillet, reduce heat to medium. Add butter and let it melt, then add minced garlic. Sauté for 30 seconds until fragrant. Stir in lemon juice, lemon zest, and broth, scraping up any browned bits from the pan. Simmer for 2–3 minutes until slightly thickened. Return the salmon fillets to the skillet and spoon the sauce over them. Cook for another 2 minutes, letting the sauce coat and glaze the salmon beautifully.
Step 4: Plate and Serve : Arrange the roasted broccoli on a serving plate. Place the salmon fillets on top or beside it. Spoon extra lemon butter sauce over the salmon. Garnish with parsley and lemon slices.