Gather all ingredients.
Make the shrimp paste: Mix shrimp, onion, water chestnuts, celery, and green onion together in a mixing bowl. Stir in crabmeat, egg, parsley, sesame oil, garlic, soy sauce, salt, and pepper.
Make the dipping sauce: Whisk soy sauce, parsley, water, sesame oil, sugar, and garlic powder together in a small bowl.
Make the toast: Heat 1/2 inch oil in a large, heavy skillet over medium heat.
Spread each slice bread with a thick layer of shrimp paste, pressing gently so it sticks to bread.
Working in batches, fry bread, paste-side down, in hot oil until golden and shrimp is pink, 2 to 3 minutes. Flip carefully and cook until bread is golden brown, about 1 minute. Drain on paper towels.
Slice shrimp toasts diagonally and serve with dipping sauce.