To make the batter in a blender, combine the eggs, salt, flour and milk in the blenderjar, and blend at high speed for 2 or 3 seconds. Turn off the machine, scrape down thesides of the jar, and blend again for 40 seconds. (To make the batter by hand, beat theeggs and salt with a whisk or a rotary or electric beater until frothy. Slowly add about a quarter of the flour , beating constantly. Then pour in a quarter of the milk in a thin stream and blend; repeat adding first some flour, then some milk, until all is incorporated andmixture is quite smooth and creamy. A few lumps are okay, since this batter will rest for an hour in the refrigerator.)
Refrigerate for at least 1 hour.
Preheat the oven to 400° F.
In a 10-by-15-by-2 1/2-inch roasting pan, heat the fat over moderate heat until itsplutters. Briefly beat the batter again and pour it into the pan. Bake in the middle ofthe oven for 15 minutes, reduce the heat to 375° F, and bake for 15 minutes longer, oruntil the pudding has risen over the top of the pan and is crisp and brown.
With a sharp knife, divide the pudding into portions, and serve immediately.