Combine the salt, spices, and thyme in a small bowl. Sprinkle the squash rounds with a teaspoon of the mix.
Divide the remaining spice mix in half and stir one half into the flour and the other half into the cornmeal.
Beat together the egg and milk.
Heat 1 inch of safflower or peanut oil in a deep saucepan or frying pan to 350 degrees.
Using your hands, quickly toss the squash in the flour and shake off excess. Toss in the milk and egg, then dip in the cornmeal to coat, shaking off excess. Deep-fry for about 2 minutes. Drain on paper towels and serve at once.