Stir fry: Caveman Style

So the problem with making stir fry paleo or close there to, is the most distinctive flavor in stir fry: soy sauce.
I tried to make a replacement that has that earthy, salty, umami favor. You have to use some other pretty powerful flavors to get something that will make up for the all that salt.
I thought it came out pretty good.

Sauce:
2 cups of beef stock unsalted
1 tbs minced ginger
1 tsp minced garlic
1 tsp minced onion
1/4 tsp red pepper flake
1 tbs apple cider vinegar
1 tsp sesame oil
1/4 tsp lime zest
1/4 tsp black pepper
Salt to liking when finished

Bring to simmer, reduce by half, remove from heat, let cool and salt to taste.

I like using sirloin sliced to 1/4 in. pieces
I used 1 lb. plus 1/2 cup of the sauce plus a little bit more fresh ginger to marinate the meat for about a hour.

In a hot wok or cast iron pan using a little olive oil, sear the beef in small batch for about 45 seconds on each side toss a few times in the pan then set aside.

Also working in small batches, using whatever vegetables you'd like, stir fry until just tender set aside.

Put a single serving of vegetables and meat in the wok and add about two tbs of the sauce. Toss allowing everything to coat and warm.

I served over some chopped romain. Well revived overall.