Slice the beef thinly against the grain. Partially freezing the meat will make it easier to slice thin. You can do a very flat bevel cut to get very thin but nicely sized pieces of beef.

In a large bowl, combine the soy sauce, lime juice, garlic, brown sugar, black pepper, Oriental 5 spice and ginger. Add the steak and mix through. Carefully place the onion slices on top to absorb some marinade, but keep them together

Allow to marinate in the fridge for 1-12 hours.

Remove the marinade; carefully remove the onion slices from the top and set on a plate. Remove the meat and put in a stainer and place the strainer over the marinade bowl to catch all of the marinade to make the sauce.

Heat a skillet over med high heat and add 1-2 Tbsp of high heat oil (I like peanut).

Carefully place the onion slices in the skillet and allow them to brown on one side for 2-3 minutes. Remove to the plate.

Make sure the meat is thoroughly drained of marinade before trying to brown it.

Cover the bottom of the skillet with meat slices and allow to sear for ~30 seconds per side. Remove to another plate and cook the rest in batches, adding oil as needed.

Reduce the heat and add the marinade and beef stock to the skillet, bring to a boil for 2-3 minutes.

Add the corn starch slurry and stir until thickened.

Nestle the meat and half of the onions back into the sauce and simmer for 30 minutes or until tender.

Add the remaining onions (seared side up) over the top of the beef and allow them to heat through.

Serve over white rice. A broccoli or cabbage salad are delicious sides.