Marinate the sliced beef flanks for at least 10 minutes. The Bicarbonate of Soda is a MUST. This tenderises the beef. Remember to sut the beef across the grains.
Before frying add in the cornflour and coat nicely before frying. Refer to pic. Fry drained and set aside on medium to high heat.
To make the sauce, a touch of sesame oil to fry the garlic and ginger first, then add all the liquid ingredients adding a touch of water to rinse out the bowl.
After simmering for about 5 minutes on low heat, sieve the sauce to remove the ginger and the garlic.
Taste your sauce, it would be stronger because the lettuce to wraps and because the beef is unseasoned. If you want a thicker sauce like me as I am not eating mine with rice, just lettuce wraps add a bit of cornflour and water slurry.
Then add in the lemon peel and turn heat off.