Preheat oven to 400 degrees. Melt the butter in a saucepan pour over broccoli along with the lemon juice, salt and pepper. Massage the broccoli vigorously with your hands until it softens and each floret is completely coated.
Line a baking sheet with parchment paper and spread florets out in a single layer. Roast for 20 min until broccoli begins to turn brown around the edges. Then remove from the oven and flip over each floret. Roast for another 15 min.