Wash the asparagus and cut off the woody ends. Cut the asparagus in half lengthwise. Peel the shallots and cut into thin rings. Heat the oil in a pan. Fry the asparagus and shallots for about 5 minutes, turning them over.
Season with salt and pepper.
Oven grill
Rub with the cut surface of the garlic halves. Spread half the sour cream on the slices of bread. First add the asparagus and shallots mixture, then the rest of the cream.
Put the breads on a baking tray covered with aluminium foil and bake under the hot grill for about 5 minutes. Serve immediately.