Makes 8 servings. Difficulty
3 Tablespoons olive oil 2 Tablespoons mustard seeds 1/3 cup red wine vinegar 1 Tablespoon sugar 1/2 red onion, thinly sliced 1 large bunch of asparagus, trimmed
Heat 1 tablespoon of the oil in a heavy skillet over medium heat until hot. Add the mustard seeds and cook, stirring, until they pop and turn 1 shade darker, about 1-1/2 minutes. Transfer oil and seeds to a large bowl.
Simmer the vinegar and sugar in a small saucepan, stirring, occasionally, for about 5 minutes or until the sugar is dissolved. Remove from the heat and set aside to let cool.
Meanwhile, heat a large pan of salted water to a boil. Add the asparagus spears and cook until just tender, about 4-5 minutes. Drain. Immediately plunge asparagus in a bowl of ice water to halt the cooking process. Let sit in the ice water for 2-3 minutes or until cool. Drain.
Heat the remaining 2 tablespoons of oil in a large skillet over medium high heat. Add the onion and cook, stirring occasionally, until golden brown, about 10 minutes. Remove from the heat and stir in the vinegar mixture. Transfer the onions to the bowl containing the mustard seeds.
Transfer the asparagus to the onion-mustard seed mixture and toss to blend. Adjust seasonings to taste with salt and freshly ground black pepper. Serve at room temperature or chilled.