Slice the eggplant into 8 rounds 1/2 inches each. Place in a colander and sprinkle salt on each side. Let sit 10 minutes to draw out some moisture. Then give them a quick rinse.
While eggplant sits, mix the breading ingredients and place on a rimmed plate or shallow bowl. Beat the egg with water in a bowl large enough to accommodate an eggplant round.
Blot all the moisture off of the surface of the eggplant slices with paper towels. Line a sheet pan with foil and spread with 1 tablespoon of oil.
Method (See Air Fryer & Pan Frying instructions in post.)
Preheat oven to 400 F.
Pick up a slice of eggplant and dip it into the egg, covering both sides completely. Let any excess egg drain off then put the eggplant into the keto breadcrumbs. Scoop the mixture on top of the eggplant (I use my fingers) and gently pat it in place. Flip the eggplant slice to make sure both sides are coated evenly. Place onto the sheet pan and repeat, coating all of the eggplant.
Bake for 6-8 minutes per side, until the coating is crispy and golden brown.
Remove the eggplant from the oven. Spoon sauce over each eggplant round. Top each with one slice of mozzarella cheese and sprinkle with Parmesan cheese.
Return to the oven and bake until the cheese has melted. Stack and serve.
Storing and Reheating
Cool Eggplant Parmesan before covering and refrigerating. Can freeze, but it will not be crispy when it thaws. To reheat, warm a leftover serving in the microwave or cover with foil and reheat in a 350 oven or convection air fryer for 20-30 minutes. Can also reheat in a drawer-type air fryer for several minutes at 350F.