Rinse the broccoli head under cold running water. Trim off the tough stem end and peel thick skin from the lower stem if desired. Cut the broccoli into uniform florets, about 1 to 1.5 inches each, so they cook evenly. If you like, slice the tender stem pieces into 1/4-inch coins and include them.

Prepare blanching water

Fill a large pot with about 4 cups of water and bring to a rolling boil. Add 1 teaspoon kosher salt to the water.

Blanch

Add the broccoli florets (and stem pieces) to the boiling water and cook for 2 minutes until bright green and just tender-crisp. Do not overcook; they should still have a slight bite.

Shock

While broccoli blanches, prepare an ice bath (bowl with cold water and a few ice cubes). Immediately transfer broccoli from the pot to the ice bath using a slotted spoon to stop cooking. Leave in the ice bath for 1–2 minutes until fully cooled, then drain thoroughly and pat dry with a clean kitchen towel or paper towels.

Seasoning & Finish

Sauté aromatics

Heat a large skillet over medium heat. Add the 2 tablespoons olive oil and 1 tablespoon butter (if using). When the butter has melted and the oil shimmers, add the minced garlic and sauté for 20–30 seconds until fragrant but not browned.

Toss and finish

Add the drained broccoli to the skillet. Toss to coat in the garlic oil and sauté for 2–3 minutes until heated through and edges develop slight golden color. Stir frequently to prevent burning.

Season

Remove the skillet from heat. Add 1 tablespoon fresh lemon juice, 1 teaspoon kosher salt, 1 teaspoon freshly ground black pepper, and 1/4 teaspoon red pepper flakes if using. Toss well to combine and taste; adjust salt or lemon as desired.

Optional garnish

Sprinkle 2 tablespoons grated Parmesan over the broccoli and toss gently so it melts slightly. Serve immediately.