Don't use pencil-thin stalks of asparagus for this dish; thicker stalks work better.
Pan Roasted Asparagus
1 T. olive oil
1 T. butter
2 lbs. thick asparagus spears, woody ends snapped off
Salt and freshly ground pepper
balsamic vinegar (optional)
Heat oil and butter in a 12-inch skillet over medium-high heat. When the butter has melted, add half of the asparagus to the pan with tips pointed in one direction; add the other half of the stalks with tips pointing in the opposite direction. Use tongs to distribute the spears evenly (they won't quite fit into one layer, but that's fine). Cover and cook until asparagus is bright green and still crisp, about 5 minutes.
Uncover the skillet and set heat to high. Season asparagus with salt and pepper. Cook until spears are tender and well browned along one side, using tongs to occasionally move spears from center to outside of pan so all the spears are browned, 5 to 7 minutes. Transfer asparagus to serving dish, adjust seasonings, and if you like, sprinkle with good quality balsamic vinegar.