In a blender jar, pulse the egg yolk, garlic, mustard, horseradish dip, salt, and vinegar to combine. With blender running on low speed, drip the olive and avocado oils in slowly, alternating. Emulsify each addition before the next. The more oil you add, the more quickly you can do it. If the sauce becomes too thick, add a few drops of water. Adjust seasoning to your taste.
Prepare your Cameron's stovetop smoker. Place a tablespoon of smoking chips in the middle of the bottom, a dripping tray on top, a smoking rack inside the tray. Season beef tenderloin with kosher salt and freshly ground black pepper and place on the rack. Secure the lid and smoke over high heat for 10 minutes. Turn off the heat and let the smoke set for the next 5 minutes with the lid still closed.
Remove the tenderloin from the smoker and slice it.
Mince the tenderloin with a knife and mix the meat to distribute the smoked and seasoned pieces withe the rest of the meat.
Grill the bread slices. To plate, spread 1 tbsp of the sauce per portion making a cirle. Place a portion of steak tartare on top.
Arrange the toppings and bread and serve.