To make the asparagus: Place a grill pan over high heat. Brush the asparagus with some olive oil and roast for 6 to 8 minutes—turning frequently—until slightly charred in places. Let them cool a little before cutting into 1½-inch (3 to 4 cm) pieces.
To make the vinaigrette: Heat the sunflower oil in a frying pan over medium-high heat, add both t