Curry Chicken–and–Sweet Potato Galette

Name: Curry Chicken–and–Sweet Potato Galette
Ingredients: 1 cup finely chopped yellow onion; ½ cup thinly sliced scallions; 2 tablespoons finely chopped garlic; 2 tablespoons curry powder, divided; 1 ½ teaspoons chopped fresh Scotch bonnet chile (optional), seeded, if desired; ½ teaspoon grated peeled fresh ginger; 1 ½ teaspoons ground allspice, divided; ½ teaspoon kosher salt; ¼ teaspoon black pepper; 2 (4-ounce) boneless, skinless chicken thighs, cut into 1-inch chunks; 2 tablespoons olive oil; ¼ cup water