Shrimp Filling
2 dried black mushrooms
1/2 pound medium-size raw shrimp, peeled, deveined, and minced
1 1/2 teaspoons cornstarch
1 egg white
1 teaspoon Shao Hsing wine or dry sherry
1/2 teaspoon minced fresh ginger
1/8 teaspoon salt
Pinch of white pepper
10 jumbo raw prawns (10 to 12 per pound)
Salt and white pepper
Cornstarch for dry-coating
Spicy Tomato Sauce
2/3 cup chicken broth
1/2 cup ketchup
2 tablespoons lemon juice
1 1/2 tablespoons sugar
1 tablespoon soy sauce
2 teaspoons Chinese mustard
Vegetable oil for deep-frying
1 teaspoon minced garlic
Tomato wedges for garnish

Soak mushrooms in warm water to cover for 30 minutes; drain.
Cut off and discard stems and finely chop caps.
Combine mushrooms and remaining filling ingredients in a medium bowl.
Set aside.
Remove prawn shells, leaving tail sections intact.
Butterfly each prawn by making a slit on the outer side of prawn and cutting almost to, but not through, inner side.
Remove sand vein.
Flatten each prawn with side of cleaver blade.
Lightly sprinkle prawns with salt and white pepper.
Stuff each prawn with 1 1/2 tablespoons of filling.
Evenly coat prawns with cornstarch.
Let stand for 5 minutes.
Combine spicy tomato sauce ingredients in a small bowl and set aside.
Cooking Set wok in a ring stand and add oil to a depth of about 2 inches.
Over high heat, bring oil to 360°F.
Add prawns, half at a time, and cook for 3 minutes or until prawns feel firm and turn pink.
Lift out and drain on paper towels.
Keep warm in a 200°F oven while cooking remaining prawns.
Remove all but 1 tablespoon oil from wok.
Reheat oil over high heat until hot.
Add garlic and cook, stirring, until fragrant, about 5 seconds.
Stir in spicy tomato sauce and cook until hot.
Pour sauce on a platter.
Arrange prawns on top of sauce.