Celebrate spring with this riot of color, served warm or cold. Kids can make the dressing in a jar and shake it up. The vinaigrette is good on salads too, so feel free to double or even triple the recipe and keep it on hand.
Add the olive oil, red wine vinegar, Dijon mustard, garlic, salt, and pepper to a small screw-top jar or plastic container. Shake it and set aside. To serve the asparagus cold, have a large bowl of ice water by the side of the stove. Bring a medium pot of lightly salted water to a rapid boil over high heat. Plunge the asparagus into the boiling water. Cook until it is tender but still firm, about 2 to 4 minutes after the water returns to a simmer, depending on the thickness of the asparagus. Drain and plunge it into the ice water. After about 5 minutes, drain and pat dry. Fan out the asparagus, tips facing the same direction, then drizzle with the dressing and sprinkle with the pepper "confetti." If you prefer to serve this warm, drain the asparagus thoroughly after boiling and lay it out directly on the platter.