Before You Start
The day before:
Whisk all ingredients together, except meat, into a large mixing bowl until they are fully combined. Using a long thin knife cut the flank steak into 4mm thick strips across the grain. The best way to achieve this is to lay the full flank steak down on a cutting board so that the grain of the meat is horizontal (left to right). Carefully slice off thin strips across the grain. Continue slicing and add all the strips to the marinade. Mix well. Pour the entire contents of the bowl into a large one-gallon resealable zip-top bag. Place the zip-top bag in a rigid container, just in case it leaks, and refrigerate overnight.
The day of:
Drain the marinated meat in a colander to remove any excess liquid. Place the solid convection steam oven pan down on the counter and set one of the wire racks over it. Lay the strips of meat one at a time across the rack. Cover the wire rack without overlapping the strips of meat. Repeat with the second wire rack and remaining strips of meat.
Carry the solid pan and two wire racks over to the convection steam oven. Place the first wire rack on position 3. Place the second wire rack on position 2 and place the solid pan on position 1. Turn the convection steam oven on by selecting the Convection Mode set to 65°C. Leave the door open in the “at rest” position (about 3 cm open). Make sure to turn off the interior light. Check the jerky after 2 hours. Rotate the wire racks. You can also remove the solid oven pan at this point. Continue dehydrating for an additional 2 hours or as necessary until the jerky is dehydrated.