1. Preheat oven to 190°C (375°F). Peel onions and skillet-glaze in butter, oil, lemon juice and 10 ml (2 tsp.) of maple syrup for about 10 minutes over medium heat.
2. In the meantime, lay puff pastry sheet on a baking sheet covered with parchment paper.
3. Fold over each edge of pastry to create a border and prick pastry bottom with a fork.
4. Combine feta, ricotta, sour cream, remaining maple syrup, thyme and oregano in a food processor. Season.
5. Spread mixture over puff pastry, then top with glazed cipollini, red pepper and broccolini. Bake for 25 to 30 minutes.
6. Garnish with fresh thyme and lemon zest to taste, then cut into small squares and serve hot or cold as a cocktail appetizer.

Aide-gourmet tip
To peel cipollini more easily, simply plunge them in boiling water for about 30 seconds.