Step 1

Combine onion, scallions, garlic, 1 tablespoon curry powder, Scotch bonnet chile (if using), ginger, 1/2 teaspoon allspice, salt, and black pepper in a ziplock plastic bag or an airtight container with a lid. Add chicken; seal and toss to fully coat. Refrigerate at least 1 hour or up to overnight (12 hours).

Step 2

Pulse flour, frozen butter, turmeric, garlic powder, thyme leaves, salt, and black pepper in a food processor until combined, about 6 pulses. Add ice water, 1 tablespoon at a time, as needed, pulsing until mixture begins to come together and resembles coarse sand. Transfer dough mixture to a lightly floured work surface; gather and knead gently until combined. (Chunks of butter should be speckled throughout.) Place dough in center of a sheet of plastic wrap; using a rolling pin or your hand, flatten dough into a 1-inch-thick disk. Wrap tightly in plastic wrap. Refrigerate until firm, at least 1 hour or up to overnight (12 hours).

Step 3

Process parsley, chopped bell peppers, red and white onions, scallions, garlic, ginger, oil, lime juice, Scotch bonnet chile (if using), salt, and thyme in a blender or food processor until smooth, about 30 seconds. Refrigerate in an airtight container until ready to use or up to 3 days.

Step 4

Preheat oven to 375°F. Toss together sweet potato, oil, garlic powder, ginger, smoked paprika, and salt a large bowl until coated. Transfer to a baking sheet lined with parchment paper. Roast in preheated oven until golden brown and tender, about 15 minutes. Let cool about 15 minutes.

Step 5

Heat oil in a large skillet over medium. Add remaining 1 tablespoon curry powder and remaining 1 teaspoon allspice to oil, and cook, stirring constantly, until spices begin to toast and darken, about 1 minute. Remove chicken from marinade; brush off and discard excess marinade. Add chicken to skillet, stirring to coat in oil mixture. Cook, stirring occasionally, until chicken begins to brown, 2 to 3 minutes. Add 1/4 cup water; cover and cook until chicken is tender and an instant-read thermometer inserted in thickest portion of meat registers 160°F, 6 to 8 minutes. Uncover skillet; cook, uncovered, stirring occasionally, until liquid is reduced, about 1 minute. Remove from heat; let cool slightly, about 10 minutes.

Step 6

Stir together sour cream, green seasoning, turmeric, garlic powder, salt, and black pepper in a small bowl until well combined. Set aside.

Step 7

Roll savory pastry dough out into a 12-inch circle on a lightly floured work surface. Transfer pastry to a rimmed baking sheet lined with parchment paper. Spread 1/4 cup seasoned sour cream over pastry, leaving a 2-inch border. Arrange sweet potato filling on sour cream within border. Top with cooked chicken. Arrange bell pepper slices on and around chicken.

Step 8

Fold pastry edges up and over the outer 1-inch edge of galette, pleating crust as needed. Brush top of pastry with beaten egg. Bake at 375°F until crust is golden brown and bell peppers are starting to wilt and brown, about 45 minutes. Remove from oven. Let rest 5 to 10 minutes. Serve warm or at room temperature with additional seasoned sour cream and green seasoning.