Step 1

If time allows, place the steaks on a large plate and freeze until semi-firm, about 35 minutes (this makes them easier to slice). Slice the steaks into ¼-inch-thick slices.

Step 2

Combine 1½ tablespoons of water and the baking soda in a medium bowl. Add the beef slices and toss to coat. Let sit at room temperature for 5 minutes.

Step 3

Meanwhile, in a mini food processor or blender, combine the 1½ tablespoons vegetable oil, sesame oil, soy sauce, sugar, garlic, shallot, ginger, and red pepper flakes; process until smooth. Pour the mixture over the beef and toss to coat evenly. Cover with plastic wrap and marinate in the refrigerator for at least 1 hour or overnight.

Step 4

Turn on the exhaust fan. In a large (12-inch) cast iron or nonstick skillet over medium-high heat, heat the remaining 2 teaspoons of oil until very hot and shimmering. Add half of the beef slices in a single layer and cook, without stirring, until browned on one side, 2 to 3 minutes. Stir the meat and continue stir-frying until the beef is just cooked through, 1 to 2 minutes longer. Transfer the beef to a serving platter and cover to keep warm; repeat with the remaining beef (no need to add more oil to the pan), adding any marinade left in the bowl to the pan right before stirring the meat. Transfer the second batch of beef to the serving platter and sprinkle with the scallion greens and sesame seeds. Serve immediately.

Step 5

Note: Check out easy guidance on how to peel, grate, and chop fresh ginger here.