Step 1: Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper for easy cleanup.
Step 2: Wash and thoroughly dry the broccoli florets. This is crucial for crispiness; wet broccoli will steam instead of roast. Ensure florets are uniform in size.
Step 3: In a large bowl, combine the dried broccoli florets with 2 tablespoons of olive oil, the minced garlic, salt, black pepper, and red pepper flakes (if using). Toss everything thoroughly with your hands to ensure every floret is evenly coated.
Step 4: Spread the seasoned broccoli in a single layer on the prepared baking sheet. Do not overcrowd the pan; use two sheets if necessary to ensure proper roasting and prevent steaming.
Step 5: Roast for 15-20 minutes, or until the broccoli is tender-crisp and lightly charred at the edges. Halfway through, give the pan a good shake or use a spatula to flip the florets for even browning.
Step 6: Remove the baking sheet from the oven. Immediately transfer the roasted broccoli to a serving dish. Squeeze the fresh lemon juice over the hot broccoli and sprinkle with lemon zest. Toss gently to combine and serve immediately.