Spiced Crab Cakes with Tamarind Mayonnaise

Name: Spiced Crab Cakes with Tamarind Mayonnaise
Ingredients: 4 tablespoons vegetable oil; 1 small onion, finely chopped; 1 Thumb-size piece fresh ginger, peeled, and finely chopped; 2 small cloves garlic, finely chopped; 2 teaspoons ground coriander; 1/4 to 1/2 teaspoon red chile powder; 1 teaspoon garam masala; Kosher salt; 2 tablespoon fresh lemon juice; 1 ounce fresh cilantro leaves and stalks, chopped; 14-ounces prepared crab meat; 1 large free-range egg; 2 1/2 tablespoons mayonnaise; 9 to 10 pieces of thick bread, made into crumbs in a food processor; 3 ounces prepared mayonnaise; 2 ounces or 1/4 cup milk; 1 tablespoon tamarind paste,* or to taste; 1/4 teaspoon freshly ground black pepper; Handful fresh cilantro leaves and stalks, chopped; Lightly dressed fresh salad leaves, to serve