Ok, ok, I’ll give.
1/2 cup duck fat, slightly above room temp
4 large egg yolks
1 1/2 T dusseldorf or dijon mustard
Juice of one lemon
Salt and pepper to taste
Blend all the ingredients except the duck fat. Then slowly drizzle the duck fat into the egg mixture while blending. Viola! Duckinnaise.
I use my immersion blender and the tall measuring cup that comes with it. You can also use a regular blender or a food processor. (Or a whisk if you have forearms like Popeye). You don’t want to overwhip the egg yolk mixture but blend it enough so that the ingredients are thoroughly disbursed and the mixture is smooth. That’s when you start drizzling in the the duck fat.