Cut the sinew of the pork with a knife, and then pound it with a meat tenderizer.
Place the pork, miso paste, sake, mirin, sugar, and grated ginger into a storage bag and knead them together well. Marinate for 1 hour at room temperature, or for a few hours to overnight in the refrigerator.
Remove excess seasonings from the pork by scraping with a spoon to avoid burning while cooking.
Heat oil in a frying pan over medium-low heat. Add sliced garlic and cook until golden brown. Remove the garlic, then add the pork. Cook, covered, over low heat until nicely browned. Turn the pork over and cook the same way, covered, until nicely browned on the other side.
Slice the pork into 6-8 strips. Serve with the fried garlic.