In a large bowl, combine evaporated milk, egg, green pepper, and onion.

Stir in crushed saltine crackers, salt, ground mustard, and pepper.

Crumble lean ground beef over the mixture and mix well.

Pat the mixture into an ungreased 8x4-inch loaf pan.

Bake, uncovered, at 350°F (175°C) for 1 hour and 15 minutes, or until no pink remains and a thermometer reads 160°F (70°C).

Drain any excess fat.

Let the loaf stand in the pan for 10 minutes.

Meanwhile, in a small saucepan, combine the tomato soup, ketchup, and horseradish.

Cook until heated through, stirring occasionally.

Turn the meatloaf out onto a serving platter.

Spoon 1/2 cup of the hot sauce over the loaf.

Serve the remaining sauce with the meatloaf.