Slice the tofu crosswise into half an inch thick and fry in oil until golden brown. Cut into smaller pieces and set aside.
In a large pan or wok, saute onions in 2 tablespoons of oil followed by the garlic. Add pork, season with salt and pepper and cook for 5-10 minutes or until cooked through and starting to brown**. Add carrots and stir for one minute. Place the cabbage, celery and season with half a teaspoon of pepper and 1 tablespoon of soy sauce. Cook for one minute. Scoop the vegetables and leave the remaining liquid in the pan.
Add chicken stock just enough to make the liquid 6 ½ cups total. Bring to a boil and season with soy sauce (if needed). Once boiling, add dry noodles and stir around to submerge every piece. Separate strands using 2 wooden spoons. Once most of the liquid is absorbed, taste the noodles and season with salt and pepper accordingly. Add more chicken stock if needed.
Put about ⅔ of the cooked vegetables back and stir to combine. Turn heat off and transfer the pancit to a serving platter. Spread the reserved cooked vegetables on top and sprinkle with fried tofu and green onions. Serve with lemon slices.