Slice tempeh as thin as possible without breaking. Then, place them in the boiling water for 1-2 minutes and drain. Keep them aside.
In a mixing bowl combine all the marinade ingredients (except salt). Do a taste testing at this stage and then decide whether you want it salty or just as is. Depending on your taste add salt and whip it up.
Then add tempeh slices to the marinade making sure that each slice is well soaked.
Place the tempeh slices in the Air Fryer basket. With a spoon pour the leftover marinade on the tempeh slices.
Place the basket inside the air fryer and turn it on. Air fry it at 350 degree for 12 minutes. Pause it and take the basket out. Check it whether it is desired crispy. If you want it crispier then place the basket again in the air fryer again and turn it on for another 3 minutes. ( Do not exceed 15 minutes as it will have a burnt taste)
Once done, turn it off and take out the basket. Enjoy it immediately in a sandwich, salad or as a side with scramble.
For oven baked option: Follow until step 3. Then place the tempeh slices on the greased baking sheet. With a spoon pour the marinade on each tempeh slices. Place the baking sheet in a preheated oven at 400-degree Fahrenheit for 20 minutes.
For pan fry option: Follow until step 3. Then, Heat the 1-2 tbsp olive oil in a nonstick pan on a medium-high flame. Then, place tempeh slices on the pan. Pour the leftover marinade on tempeh slices with a spoon and cook for about 5 minutes. With the help of a flat spatula or tongs flip the tempeh slices to the other side and cook again for 5 minutes or until nicely browned and crispy.
Salt is absolutely optional in this recipe. We, prefer these without salt since the marinade is quite salty. So, use salt sparingly or not at all depending on your taste.
I personally air fry my tempeh bacon for 15 minutes because I like it crispier. Make sure to check after 12 minutes of air frying to make sure its not burnt.
I have provided step wise images in the post above for your reference.