Heat vegetable oil in a small saucepan over medium heat. Add finely chopped red onion and sauté 2–3 minutes until translucent. Stir in grated ginger and minced garlic and cook 30 seconds until fragrant.

Add diced mango, brown sugar, apple cider vinegar, lime juice, ground cumin, red chili flakes, and salt. Stir to combine.

Bring mixture to a gentle simmer, reduce heat to low, and cook uncovered 12–15 minutes, stirring occasionally, until mango is soft and mixture has thickened to a jammy consistency. Taste and adjust salt, sugar, or lime juice as needed. Remove from heat and let cool to room temperature (will thicken more as it cools).

Puff Pastry & Brie

Prepare oven and pastry

Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper. Lightly dust a work surface with 1 tbs flour.

Unfold the thawed puff pastry sheet and roll lightly to even thickness. Using a 2.5-inch (6 cm) round cookie cutter or a knife, cut out 12 rounds. Re-roll scraps once if needed and cut additional rounds.

Prepare brie

Slice the triple-cream brie into 12 pieces about 3/8–1/2 inch thick (enough to sit on each pastry round). If brie has a very thick rind you may trim lightly, but leaving the rind is fine.

Assemble bites

Place pastry rounds on prepared baking sheet. Place a brie slice in the center of each round. Spoon about 1/2 teaspoon of the cooled spiced mango chutney on top of each brie slice, leaving a small border of pastry visible.

Egg wash & bake

Whisk the egg with 1 tsp cold water to make an egg wash. Brush the exposed pastry edge lightly with egg wash (avoid too much on the cheese). Optionally sprinkle a few toasted sesame seeds or chopped pistachios on top of the chutney. Bake in preheated oven 12–15 minutes, until pastry is puffed and golden and brie is soft. Remove from oven and let cool on the sheet 2–3 minutes before transferring.

Assembly & Garnish

Transfer bites to a serving platter. Garnish each with a small cilantro leaf if using. Serve warm so the brie is gooey with the tangy-spiced mango chutney.

Leftover chutney can be refrigerated in an airtight container up to 1 week. Baked bites are best served the day of preparation; reheat briefly in a 350°F (175°C) oven for 5–7 minutes to revive pastry and cheese.