1Combine shrimp, egg, soy sauce, scallions, cornstarch, sesame oil, and garlic in the bowl of a food processor. Pulse until finely minced. Alternatively, chop shrimp by hand with a knife until extremely finely minced, then fold in remaining ingredients in a medium mixing bowl.
2Spread mixture evenly over one side of each piece of bread. Dip shrimp side into sesame seeds to coat if desired.
3Heat oil in a wok or dutch oven to 325°F (use a thermometer). Carefully transfer half of the toasts to the oil, shrimp side-down. Cook until golden brown, about 2 minutes, adjusting flame as necessary to maintain heat, then carefully flip toast and cook until the second side is golden brown, about 1 minute longer. Transfer to a paper towel-lined plate and repeat with remaining toasts. Season with salt and serve immediately.