Hot Deviled Egg Sandwiches (makes six)
6 large slices rustic French bread
6-8 hard-boiled eggs, cooled, shelled, and sliced or cut each into about 8 pieces
1 small onion, peeled, cut in half, then cut into thin slices
3 cups milk, heated to warm
4 tablespoons butter, plus extra for spreading on the bread
6 tablespoons flour
One half teaspoon salt
One half teaspoon to three-quarters teaspoon dry mustard powder, or one and a quarter teaspoons prepared Dijon-style mustard
One quarter teaspoon hot sauce (more if you’d like)
One cup grated Swiss cheese
One-third cup grated Parmesan cheese
Toast the bread. While it’s still warm, butter it. Set aside. To make the sauce, first melt the 4 tb of butter in a medium-sized saucepan. Saute the onion in the butter until it’s lightly browned. Meanwhile, stir a half teaspoon of the mustard powder and the salt into the flour, then add the flour/mustard/salt to the browned onion, and whisk over low heat for at least two minutes, to cook the flour without browning it. Add the warm milk and keep whisking, turn the heat up to medium-high and cook until the mixture thickens. Add the hot sauce, then the Dijon if you’re using that instead of mustard powder, then the Parmesan cheese and whisk until melted. Taste for mustard – if you want more, dissolve the remaining quarter teaspoon of mustard powder in a teaspoon of water and whisk it into the sauce, or add a little more Dijon. Taste for heat and salt and add a little more of either if you like.
If your broiler is large enough to sit over six slices of bread, adjust the oven rack to about six inches below the broiler, then preheat the broiler. If not, preheat the oven to 450 degrees F. Place the bread slices, buttered side up, on a baking sheet. If you’ve chopped the eggs, mix them with just enough sauce to moisten them. Divide the egg mixture (or sliced eggs not mixed with sauce) among the bread slices, top with sauce, then the Swiss cheese. Broil for a few minutes, watching carefully, until browned and bubbly. If you’re baking them, it may take up to 10 minutes, but keep watching. Let the sandwiches cool for a couple of minutes, then serve.