Scallops with Avocado and Spicy Tomato Sauce

Ingredients 
 1 tablespoon extra-virgin olive oil 
 2 tablespoons finely diced red onion 
 1 tablespoon minced seeded jalapeño 
 4 plum tomatoes—3 coarsely chopped, 1 halved, seeded and finely diced 
 1 tablespoon hot water 
 3 1/2 teaspoons fresh lime juice 
 Salt and freshly ground pepper 
 1/2 Hass avocado, peeled and finely diced 
 1 tablespoon finely chopped cilantro 
 12 large sea scallops (1 pound) 

 Heat 1 teaspoon of the olive oil in an 8-inch skillet until shimmering. Add 1 tablespoon of the diced red onion and 1/2 tablespoon of the minced jalapeño and cook over moderately high heat, stirring constantly, until the onion is golden, about 4 minutes. Add the coarsely chopped tomatoes and the hot water and cook, stirring, until the tomatoes are just softened, about 3 minutes. Transfer the mixture to a blender or food processor and puree until smooth. Strain the sauce through a fine sieve set over a bowl, pressing on the solids. Stir in 1/2 teaspoon of the lime juice and season the tomato sauce with salt and pepper. 
 In a small bowl, gently toss the diced avocado with the diced tomato, chopped cilantro and the remaining 1 tablespoon of red onion, the remaining 1/2 tablespoon of jalapeño and the remaining 3 teaspoons of lime juice. Season the avocado salsa lightly with salt and pepper. 
 Heat the remaining 2 teaspoons of olive oil in a large, heavy skillet until shimmering. Season the scallops with salt and pepper and cook over high heat until the scallops are browned and crisp on the bottom, about 3 minutes. Turn the scallops and cook until just cooked through, about 2 minutes longer. 
 Spoon the tomato sauce into the center of 4 dinner plates and mound the avocado salsa in the center. Arrange 3 scallops around the mounds of avocado salsa and serve.