Have ready, cooked beforehand, the hard-boiled eggs; cut them carefully into halves lengthwise, remove the yolks, and press them through a small sieve. Soak the anchovies, then dry and remove the bones and chop them with the mushrooms and capers; mix in the sifted yolks, add a seasoning of salt, pepper and paprica, and tarragon vinegar. This work may be done some hours before the time of serving. Have a little oil or clarified butter in the blazer, and sauté in it some rounds of bread — one for each half of an egg. When the bread is of good color on one side, turn it and place half an egg — the space from which the yolk was taken being filled with the anchovy mixture — on the bread; cover the blazer, and, when the second side of the bread is browned nicely and the egg hot, serve at once.