Place slices of green tomatoes on a baking sheet lined with a double layer of paper towel. Put another double layer of paper towel on top of them and lightly press to absorb a little moisture. Set aside.
Combine flour, garlic powder, cayenne, paprika, salt and pepper in a shallow dish and whisk together. Set aside.
In a separate dish, whisk egg and milk together.
In a third dish (it will be worth the dirty dishes, I promise) add the breadcrumbs. (see note)
Lightly season tomatoes on both sides with salt and pepper. Dredge through flour mixture, shaking off any excess.
Then dip into egg mixture and coat with seasoned breadcrumbs. (see note)
Heat a large skillet (I prefer cast iron) with enough oil to go about 1/4 inch up the side. Heat oil on medium high heat (350 degrees with a thermometer) and carefully slide tomatoes slices into the oil, dropping them in away from you, not toward you. If the oil splashes, it will not splatter you, but the back of the stove.
Fry until golden and crispy, then flip over (see above!) and fry until crispy on the other side.
Remove and place on a bed of paper towels to absorb excess oil. Serve immediately.