In a preheated oven (180°~190°C) brush 2 pieces of garlic and all the portobello mushrooms with oil and cook for 10 minutes.
Finely chop the parsley, 2 remaining garlic, and onion. In a large bowl, put the ground meat, parmesan cheese, chopped ingredients in and add the mirin, sake, balsamic vinegar, fish sauce, and black pepper and mix well with your hands or a tool. Cool in the refrigerator for a +1 hour.
For the sauce, mix the mayonnaise, seed mustard, honey, lemon juice, and mash the roasted garlic in. Lightly mix in the chives.
On the cooked portobello mushroom, place the lettuce, tomato, cheese, burger patty, sauce, and top with another portobello mushroom.