Thinly slice the beef about 1/4 inch thick, then toss with 1 tbsp of the soy sauce.
Sprinkle the beef evenly with the cornstarch and mix well.
Evenly spread the beef out on a wire rack set atop a sheet pan, and place the beef in the freezer for 30 minutes.
Use a vegetable peeler to peel the orange zest from the orange, taking care not to get any of the bitter white pithy part. Only peel off the orange colored part.
Thinly slice the orange peels into long strips.
Cut the orange in half and juice it, measuring out 1/4 cup of juice.
Place the juice in a bowl and add the remaining 2 tbsp of soy sauce, molasses, brandy or red wine, rice vinegar, and sesame oil, and whisk to combine.
Heat a large skillet over medium heat, and add a tablespoon of tallow or vegetable oil. Add the orange strips and jalapeño and sauté for 2 minutes.
Add the garlic, ginger, and red pepper flakes, and stir for 30 seconds until aromatic.
Add the prepared sauce mixture to the pan, then turn off the heat.
Heat a deep fryer to 375 degrees F (or simply fill a pot with a couple inches of tallow or oil) and set up a sheet pan lined with paper towels for drainage.
Once the fat in the fryer has reached the proper temperature, fry about 1/4 to 1/3 of the beef at a time for about 2 minutes, making sure to stir gently so the beef doesn’t stick together. After 3 minutes the beef should be golden brown and crispy.
Remove the beef to the paper towels to drain, and cook the remainder of the beef.
Reheat the sauce over medium high heat for a minute or two until bubbling again, then add all of the beef, stirring to coat in the sauce for about 2 minutes. The cornstarch from the meat should thicken the sauce slightly.
Serve immediately, preferably with rice. Enjoy!
Notes
Storing leftovers: Keep in an airtight container in the fridge for up to 5 days. Note that it will not be crispy when you reheat it, since the beef has been sitting in sauce.Freezing: Keep in an airtight container for up to 3 months. Note that it will not be crispy when you reheat it, since the beef has been sitting in sauce. To thaw, leave in the fridge overnight.Reheating: Stir fry in a skillet over medium heat for about 5 minutes, until warmed through. Or, microwave gently at 50% power until the beef is just warmed through. You want to be very careful not to overdo it, and time required ultimately depends on your serving size and the wattage of your microwave.Alternate cuts: I use sirloin because it’s a more economical cut that still has great flavor and decent tenderness. However, you may also use thinly sliced ribeye, NY strip, or even tenderloin.Frying Oil: I personally recommend using tallow (aka beef fat) for frying, as it's a highly stable fat that's not easily prone to oxidation like vegetable oils are. Add enough to your pot or fryer so that it comes 2 inches up the side of the pan.Recipe adapted from the February 2013 issue of Cooks Illustrated.