Pat the chicken breasts dry with paper towels and place them on a cutting board.

Slice each chicken breast into 4 to 5 bite-sized chunks, aiming for roughly uniform sizes about 1.5 inches wide.

Using a meat mallet or the bottom of a heavy pan, gently flatten each piece to about 1/2 inch thick.

Pour flour into the first shallow bowl, beat the eggs in the second bowl, and mix breadcrumbs with salt, pepper, garlic powder, and onion powder in the third bowl.

Dredge each chicken piece in flour, tap off excess, dip in the beaten eggs, then coat thoroughly with the seasoned breadcrumb mixture, pressing gently.

Pour about 1.5 inches of oil into a deep skillet and heat to 350°F (175°C), using a thermometer to verify.

Carefully place 4 to 5 nuggets into the hot oil without overcrowding. Fry in batches to maintain oil temperature.

Fry for 2 to 3 minutes, then flip and cook an additional 2 minutes until all sides are deep golden brown and the internal temperature reaches 165°F (74°C).

Remove nuggets with a slotted spoon and place on a wire rack set over paper towels to drain and keep crispy.

Keep cooked nuggets warm in a 200°F (93°C) oven while frying remaining batches.