Game plan: The vegetables can be served immediately or prepared 2 days in advance and served chilled or at room temperature.
- 1Bring a medium pot of heavily salted water to a boil over high heat.
- 2Meanwhile, place olive oil, parsley, capers, lemon juice, and shallot in a large nonreactive bowl and stir to combine. Season with salt and freshly ground black pepper; set aside.
- 3When the water is boiling, add broccoli and cauliflower and cook until fork tender, about 4 minutes. Drain and spread out on a baking sheet until cooled slightly, about 5 minutes.
- 4Add vegetables to vinaigrette and toss to evenly coat. Season with additional salt and freshly ground black pepper. Serve warm, at room temperature, or chilled.