1) Whisk the tempura ingredients together and let chill.
2) Heat the peanut oil in a deep-fryer or a large Dutch oven to 190C/Gas 5.
3) In a shallow tart dish, add the flour and 1 tablespoon of the Cajun seasoning and mix well.
4) Season the okra with 2 tablespoons of the Cajun seasoning. Dip the okra in the seasoned flour and then in the tempura batter and place in the oil, one at a time, and fry until golden, about 4 minutes. Remove to a paper towel-lined sheet tray. Season with salt.
Serve with the green onion dipping sauce.
Green onion dipping sauce:
In a medium sized bowl, whisk together all of the ingredients.