Cook tortellini according to package directions and drain. Set aside.
Combine egg and milk in a small bowl.
Combine panko breadcrumbs, Parmesan cheese, garlic, and salt into a zip top bag.
Dip several tortellini into egg mixture and toss into bag with bread crumb mixture. Shake to coat and set aside in a single layer. Repeat with remaining tortellini.
Add oil to a heavy saucepan and heat oil to 350 degrees.
Fry in small batches, turning to cook on both sides, about 1 minute. Remove to a paper towel lined tray to drain.
Serve immediately with marinara or ranch dressing.