Strawberry Barbecue Beef

Preheat the oven to 400 degrees F (200 degrees C). Line the bottom and sides of a rimmed baking sheet with parchment paper to catch all the cooking liquid. Arrange halved strawberries on baking sheet. 

Roast in the preheated oven until fragrant, soft, and caramelized, about 20 minutes. 

For sauce, transfer roasted strawberries and their juices to a small saucepan. Stir in water, ketchup, brown sugar, 2 teaspoons basil, 2 teaspoons vinegar, 1 teaspoon garlic, white pepper, and 1/8 teaspoon salt. Bring to a boil. Reduce heat to medium-low and simmer, stirring occasionally, 20 minutes. Remove from heat, let cool slightly, then transfer sauce to a food processor or blender. Blend until smooth. 

Preheat an outdoor grill to medium-high heat, 375 to 400 degrees F (190 to 200 degrees C). Oil grill grates. Sprinkle 1/4 teaspoon salt and the black pepper over steak. Grill steak, covered, 10 minutes. Turn steak and brush lightly with sauce. Continue cooking, brushing with sauce every 3 minutes, about 10 minutes more. An instant-read thermometer inserted into thickest part should register 130 degrees F (54 degrees C) for medium-rare or 140 degrees F (60 degrees C) for medium. 

Transfer steak to a cutting board; cover loosely with foil and let rest 10 minutes. (After resting, temperature should register 135 degrees F (57 degrees C) for medium-rare or 145 degrees F (65 degrees C) for medium.)

For salsa, toss together chopped strawberries, cucumber, onion, the remaining 2 tablespoons each basil and vinegar, and the remaining 1 teaspoon each garlic and salt in a medium bowl. Chill salsa, covered, up to 4 hours.

Thinly slice steak. Serve with strawberry salsa and garnish with additional basil.