Prep the shrimp: Pat shrimp dry with paper towels.
Remove tails. If you don’t have a food processor, rough-chop the shrimp until it forms a chunky paste.
Make the shrimp mixture: In a food processor, add shrimp, egg white, mayonnaise, sesame oil, soy sauce, garlic, ginger, sugar, pepper, and cornstarch. Pulse until it forms a thick, slightly sticky paste.
Fold in the scallions by hand so they stay visible and fresh.
Prep the bread: Trim crusts if you want clean edges (optional). Cut each slice into triangles or keep whole for larger toasts. Day-old bread helps keep the base crisp.
Spread evenly: Divide the shrimp mixture over the bread in a thin, even layer—about 2 to 3 tablespoons per slice.
Aim for a layer no thicker than 1/4 inch so it cooks through quickly.
Add sesame seeds: Sprinkle sesame seeds generously over the shrimp side. Press gently so they stick.
Preheat the air fryer: Set to 375°F (190°C) for 3 minutes. A hot basket helps the bottom toast right away.
Arrange in the basket: Lightly mist the basket with oil.
Place toasts shrimp-side up in a single layer, leaving space between pieces. Lightly mist the tops with oil to encourage browning.
Air fry: Cook at 375°F for 6 to 9 minutes. Start checking at minute 6.
The shrimp topping should turn opaque and lightly golden, and the bread edges should be crisp. If your bread is thick or the layer is heavy, add 1 to 2 more minutes.
Optional flip: If the bottoms aren’t crisp enough, flip for the last 1 to 2 minutes. Keep the shrimp side up for most of the cook to protect the topping.
Finish and serve: Let toasts cool 2 minutes so the topping sets.
Slice if needed. Serve hot with sweet chili sauce, soy-vinegar dip, or a squeeze of lime.