Lemongrass Shrimp on Toast

Name: Lemongrass Shrimp on Toast
Ingredients: 8 macadamia nuts, chopped; 3 medium shallots, chopped; 3 garlic cloves, chopped; 2 small dried red chiles, crushed; 2 tablespoons minced fresh lemongrass bulb; 1 tablespoon minced fresh ginger; 1 tablespoon fresh lime juice; 1 tablespoon sugar; 1/2 cup unsweetened coconut milk; 1 teaspoon freshly ground pepper; Kosher salt; 1 pound medium shrimp, shelled and deveined; 2 tablespoons vegetable oil; 6 thin slices of white sandwich bread—crusts removed, toasted and cut into 4 squares each; 1/2 cup crème fraîche; Cilantro leaves, for garnish