Shrimp and Tilapia Burgers

These juicy burgers are a flavorful diversion from the typical beef kind.

Recipe from Fish Without a Doubt, Houghton Mifflin 2008.

SERVINGS
4

INGREDIENTS
1/2 pound tilapia fillets
1/2 pound medium (31-35 count) shrimp in the shell
1/2 teaspoon minced garlic
1/2 teaspoon grated fresh ginger, or more to taste
2 teaspoons soy sauce
Coarse salt
1 large egg white, beaten until frothy
1/3 cup heavy cream
3 scallions, chopped
Freshly ground white pepper
Vegetable oil for sauteing
Chipotle sauce (recipe below)

For chipotle sauce:
1 large egg yolk
1/4 cup rice vinegar
2 tablespoons fresh lime juice
3/4 cup chopped fresh cilantro (use all but the toughest stems)
2 tablespoons chopped shallot
1 tablespoon chopped garlic
1 chipotle in adobo 1/4 teaspoon adobo sauce (from the can) 1 cup vegetable oil Coarse salt

For serving:
Grilled flatbread or pita breads
Chipotle Sauce
Leaf lettuce
Sliced ripe tomatoes

PREPARATION
For chipotle sauce:
1. Put the egg yolk, vinegar, lime juice, cilantro, shallot, garlic, chipotle, and adobo sauce in the jar of a blender. Blend on medium speed until you have a smooth paste.

2. With the blender still on medium, start drizzling in the oil slowly. When you've added about half the oil, crank the blender speed to high and pour in the rest of the oil in a steady stream. Taste, season with salt, and taste again. This sauce keeps for at least a week, tightly covered, in the refrigerator.

For the burgers:
1. The key to a successful fish mousse is keeping everything cold, so put the bowl and steel blade from your processor into the freezer while you prep the ingredients. And put the tilapia in the freezer while you prep the shrimp so it will be easier to dice.

2. Shell the shrimp, de-vein them if you can see the veins, and coarsley chop the shrimp. Put in a small bowl and pop it into the freezer for 10 to 15 minutes.

3. Sharpen your knife and slice the tilapia into 1/3 inch strips. Then cut the strips into 1/3 inch dice, place in a bowl, and refrigerate.

4. Fill a bowl with ice and some water. Set a smaller stainless steel bowl on the ice. Check the shrimp. If it feels firm and partially frozen, you're ready to go.

5. Set up the processor. Add the shrimp, garlic, ginger, soy, a pinch of salt, and 1 tablespoon of the egg white. Pulse to chop the shrimp well. It is chopped enough when it starts to gather in a ball on the blade. Now, with the processor running, gradually pour in the cream.

6. Scrape the mousse out into the bowl set over ice, add the scallions and some white pepper, and fold well. If you've got any questions about your seasoning, now's the time to find out. Heat a small skillet over medium heat and coat it with a film of oil. Cook a teaspoon or so of the mousse until it's golden on both sides, then give it a taste. Want more pepper or more ginger? Add it.

7. Season the tilapia with a pinch of salt and fold it into the mousse. Wet your hands so the mixture won't stick to them, and form 4 burgers. You can prep the burgers up to 2 hours in advance and refrigerate them. Any longer, and the ginger will start to break down the mousse and the burgers will be grainy.

8. Heat a large skillet over medium heat. Pour a film of vegetable oil and heat until it shimmers. Add the burgers and cook until golden (not brown), about 2 minutes a side, and firm (like the flesh at the base of your thumb).

To serve, slather each flatbread or pita bread with some chipotle sauce. Add a burger, some lettuce, and a thick slice of tomato.