Lightly butter then toast the buns in a heavy skillet on the stovetop and keep warm.
Cut, butterfly, and pound the pork thin, (1/4" to 3/8"), with a tenderizing mallet and place on a plate
Beat eggs and milk together and place in a large, shallow bowl or pie plate.
Put saltines in a food processor and pulse until you have a coarse to medium chop then add onion powder, garlic powder, and salt and give one or two more pulses to combine.
Put saltines in a shallow bowl or pie plate.
Put flour in a shallow bowl and set up a dredging line with flour first, eggs second and saltines last.
Heat vegetable oil to 350°-375°F preferably in a cast iron skillet or other heavy skillet.
Take one of the pork fillets and coat with flour, then place in the egg wash, let the excess drip off then place in the seasoned cracker crumbs and coat well by patting the crumbs on.
Place in the 350° oil for 1 1/2 to 2 mins. until the crumbs are browned.
Use a spatula and fork to gently turn to the other side and fry that side until browned 1 1/2 to 2 mins.
Remove from the oil and place on a cooling rack over a paper towel lined baking sheet and place in a warm oven.
Continue with the remaining pork.
Serve right away on the hamburger bun with lettuce, pickles, onion and mustard. (A tomato slice is good also).