While the water is coming up to a boil for the cauliflower, arrange the cubes of white bread on a baking sheet and lightly toast them in the oven, about 7-8 minutes. Arrange the toasted white bread on the platter along with the cubed pumpernickel, roast beef, radishes, cornichons and cauliflower.
Once the bacon is out of the oven, place half of a tomato on a long skewer followed by a piece of the bacon and the other half of the tomato. Repeat with the remaining bacon, tomatoes and skewers you should get about 16-20 skewers. Transfer to the platter with the other dipper and reserve.
Once you have all the dipper ready make the fondue: Place the yolks in a mixing bowl and reserve. Place a heat-safe fondue pot or a medium saucepot over medium heat with the flour and butter, cook for a minute, then whisk in the Dijon, hot sauce and milk.
Right before the milk comes up to a simmer, turn the heat down to medium-low and add in the cheese, slowly stirring in figure-eight motion.
Once all the cheese has melted, remove a ladleful of the hot cheese mixture and whisk it into the egg yolks then whisk the egg yolk mixture back into the hot cheese mixture. Remove the pot from the heat and top with the chopped scallions.
To serve, place the pot on or alongside the platter of dippers. Using fondue forks or more long skewers, dip in and munch away!