In a pot, simmer water, seasoned with all ingredients for boiling meatballs, turn off stove.
In a food processor, add everything for meatballs in and turn into paste. Squeeze paste between thumb and point finger, scoop with a spoon and drop into the pot. Repeat step until all paste turned into balls.
Bring to boil and cook for 15-20 mins. With slotted spoon, take out meatballs into a container.
In a clean pot, boil beef feet for 5 mins, take out with slotted spoon. Drain water, rinse pot, and fill up with clean water (3 quart)
Add in back the feet, season with all that are listed for broth. Boil for 15 mins.
To serve, place vermicelli in a bowl, top with meatballs, pour hot boiling broth, sprinkle with fried onion. Season with sweet soy sauce, Sriracha, and lemon juice, if you like.
Enjoy