In a large bowl, toss the broccoli with the oil and salt and pepper to taste. Arrange the florets in a single layer on a baking sheet and roast, turning once, for 12 minutes, or until just tender.
Meanwhile, in a small saucepan, melt the butter over medium heat. Add the garlic and lemon zest and heat, stirring, for about 1 minute. Let cool slightly and stir in the lemon juice. Place the broccoli in a serving bowl, pour the lemon butter over it and toss to coat. Scatter the toasted pine nuts over the top.