Step 1: Boil the potato sticks in salted water for 5-7 minutes until slightly tender but firm. Drain and pat dry completely.
Step 2: In a bowl, mix mozzarella and cheddar cheeses. Press a small amount of cheese mixture into the center of each potato stick.
Step 3: Set up three shallow dishes: one with flour, one with beaten eggs, and one with breadcrumbs mixed with garlic powder and paprika.
Step 4: Dredge each potato stick in flour, then dip in egg, and finally coat evenly with breadcrumb mixture.
Step 5: Heat vegetable oil in a deep pan to 350°F (175°C). Fry potato sticks in batches for 3-4 minutes until golden brown and crispy.
Step 6: Drain on paper towels, season with salt and pepper, and serve warm with dipping sauce if desired.