Cook the udon noodles according to package instructions. Reserve ½–1 cup of the cooking water, then drain.
In a bowl, whisk together the egg yolks, whole egg, grated cheese, and a generous amount of black pepper. Set aside.
In a pan over medium heat, cook the bacon until crispy. Remove and set aside, leaving about 1 tbsp of bacon fat in the pan.
Add the minced garlic and sauté until fragrant, about 30 seconds.
Add the miso paste and a splash of reserved udon water. Stir until the sauce is smooth. Lower the heat to low.
Add the cooked udon noodles to the pan and toss until well coated.
Transfer the udon to a bowl. Pour in the miso-egg mixture and toss quickly to create a creamy sauce (the residual heat will cook the eggs gently).
Add half of the bacon and toss again.
Plate the udon noodles
Grate more cheese on top
Finish with green onions and an extra egg yolk, if desired