I think its basic frying. My grandmother told me the key is to keep everything cold. So after preparing, she puts everything in the fridge for 20 minutes or so.

Sorry if my recipe is kind of vague...I'm use to just doing it and I don't have anything written down.

*Cut Veggies no more than a 1/4 inch thick. We actually do very small slices then bunch a group together to fry

*1 egg mixed with a little cold water and flour. Give up the urge to make it smooth, you want it a little lumpy

Dip your veggies in the egg mixture then roll them around in the tempura bread crumbs. (Sorry, can't think of the name but you can buy it as Safeway...it's in the Tempura box)

Make sure your Oil is SUPER hot! To test you can put a drop of your egg mixture into the oil. It should start to bubble and cook right away.

Place veggies into the oil...Don't try to fit everything into the pan at once. My pan is a medium size so I put about 8 pieces in together. Once in the oil, I only touch the vegetables twice; once to flip them, and lastly to pull them out.

Place on a paper towel to catch excess oil.

Grandmother says where I usually mess up is that after one batch, I throw a second on right away. I should let the oil heat up again.

For the dipping sauce...I'm not sure what the actual recipe is but I usually just mix the following to taste:

Shoyu
water
mirin
sugar

Ghee sounds delicious, perhaps you might want to make a topping sauce with pickled mango chutney to balance out the buttery flavor with some sour and fruity notes. Let me know how it works out.

Avocado oil I never tried.