Slice the Bánh Tét into thin slices. Heat 2 tbsp of oil in a skillet and pan-fry the slices until they are golden brown and crispy on both sides. Remove Bánh Tét and set aside.
Add 1 tbsp of oil to the same skillet. Fry the egg until the edges are crispy and the yolk is cooked to your liking. Set aside.
In a cold saucepan, combine the veggie broth, smashed garlic, mushroom, ramen seasoning packet, and dried veggie packet. Bring to a boil. Once boiling, add the ramen noodles and cook until al dente.
While the noodles cook, remove the mushroom from the pot and slice it. Set aside.
Grate parmesan cheese into your serving bowl. Remove a half cup of the hot broth and add it to the bowl. Stir vigorously until the cheese is completely melted and dissolved.
Pour the noodles and remaining broth into your serving bowl. Top with the crispy, pan-fried banh tet slices, the fried egg, the sliced mushroom, and a sprinkle of sliced green onions. Finish with a generous grating of fresh lemon zest.