While the some of the other answers point to liquid smoke or actual smoke,
I would suggest that the flavour doesn't primarily come from the smoke generated by the fire/stove, but by the wok, the oil and technique itself. Real smoke penetration is a inherently slow process. Stir frying is an extremely fast process. On one of those woks as pictured in your image, the food is cooking in seconds. Having grown up with the dish, I've had plenty of it that was cooked well but not done on a professional wok burner. I can also guarantee you that none of it ever had liquid smoke, paprika or coffee. I think what you'd lose from changing the dish's flavours would be worse than the added "smokiness".
If you do have a good wok and stove, you want to get it screaming hot. If your stove doesn't get hot enough, and your wok is oven safe, you could try preheating it in the oven (Chef Ming Tsai demonstrating this solution).
If you can't do any of the above, I would try a flat skillet as the closest western equivalent. You want to get it really hot and recover the heat quickly while you're cooking. A skillet will be better for that than a wok and a under powered stove.
From there it just comes down to finding the right balance of sauces, seasonings.