To one of the breading trays, add the flour, black pepper, and garlic salt. Stir or whisk to combine.
To a second breading tray, add the eggs and buttermilk. Whisk together.
Cut the ends off of the squash and zucchini. Slice into 1/2-inch thick coins.
Place squash coins into the egg mixture. Coat one and a time, then move into the flour mixture. Use tongs to turn them, ensuring the flour mixture coats both sides.
Add enough oil in a skillet to come about an inch up the sides of the pan. Heat over medium-high until temperature reaches 350 F.
Add flours squash coins to the hot oil one at a time until pan is full but not crowded. Fry for 3 minutes per side or until golden brown and crispy.
You do not have to use both zucchini and yellow squash. We chose both for color and presentation, but feel free to use either or.
You can use peanut, canola, or vegetable oil for frying.
You'll likely have leftover breading mixture.
It's really important to maintain the temperature of your oil in the skillet while frying squash. The temperature will fluctuate as you add and remove the squash. It's best to keep a thermometer clipped to the side of the skillet to make sure the oil stays at 350F. Work in batches to fry the squash (if needed) instead of crowding the pan.