1. Prepare macaroni, al dente, according to package directions. Drain and rinse under cold water.
2. In a large pot, melt butter. Add in flour and whisk together until smooth. Whisk in milk, stirring constantly until smooth and thickened, about 2 minutes. Remove from heat. Add in cheeses and stir until melted and smooth. Season with salt, pepper, and mustard.
3. Add macaroni to the cheese sauce and mix well. Pour into a 9×13-inch baking pan and refrigerate, covered, for 2 hours.
4. Prepare 3 Gefen Parchment-lined baking sheets. Using a small scoop, begin to make small balls with the cold macaroni and cheese mixture. Place them on the baking sheet. If time allows, freeze the balls before breading, as it will help you achieve a very even coating. If pressed for time, form your balls and continue.
5. In a small bowl, mix the eggs, 2 Tbsp milk, and spices for egg wash. Pour the seasoned bread crumbs into a medium-sized bowl.
6. Place the balls in the egg mixture and coat completely. Then toss into crumbs and coat well.
7. Prepare a medium-sized pan. Fill 1/3 of the way with canola oil. Heat to medium-high. Drop mac-and-cheese balls in a few at a time. Fry for 3–5 minutes. Remove with a slotted spoon and drain on paper towels.