Make sure puff pastry or crescent dough is fully thawed but still cold for easier handling. Don’t overfill pastry cups to avoid leakage. Use a sharp knife to cut brie cubes uniformly. Chop nuts finely to ensure they stick well. If sea salt flakes are unavailable, kosher salt works as a substitute. For a festive look, brush pastry edges with egg wash before baking. Fresh rosemary is optional but recommended for aroma. Variations include swapping cheese or fruit spreads, using different nuts, or making a vegan version with plant-based alternatives. Store leftovers in an airtight container in the refrigerator for up to 2 days, reheat in the oven at 350°F (175°C) for 8-10 minutes. Avoid microwaving to keep pastry crisp.