Mushroom & caramelized onion tartlets

These tartlets are my go-to potluck food! They are easy to make, easy transport, look cute as, and they don’t need reheating in case I can’t use the oven at the potluck host.

They’re also a great meat-eater-pleaser thanks to the mushrooms “meaty” consistency and the yummy tastes of caramelized onions and wine.

// Enjoy, Pia

Mushroom & caramelized onion tartlets

Cooking: 45 min // Serving: 18 tartlets


2 sheets of puff pastry
3 tbsp cooking oil
1-2 onions, any kind
1 tbsp brown sugar
3 tbsp cooking oil
500 g mushrooms
1 cup of wine, red or white
4-5 twigs of thyme
3-4 garlic cloves
2 egg


1. Start by thawing the puff pastry sheets
2 sheets are usually enough with store-bought frozen puff pastry. If you’re using homemade puff pastry, 2 sheets/squares of less than 100 g each should be enough.

2. Cut the onion in thin slices
Thin and even slices are better to speed up the caramelization process.

3. In a pan at medium heat, add 3 tbsp of oil and the onion
Make sure the temperature isn’t too high so the onion can sit a caramelize slowly while you prepare the rest of the food.

4. Add brown sugar
The brown sugar will help speed up the caramelization process. If you don’t have brown sugar, you can use white sugar or balsamic vinegar. Note the caramelization process will happen slower with balsamic vinegar though.

5. Cut the mushrooms in thin slices
Use a mandolin if you have one to speed up the process. Same as with the onion, make sure the mushroom is cut evenly in small slices.

6. Preheat the oven at 180°C (350°F)

7. In another pan, add 3 tbsp of oil and fry the mushroom
It won’t need to cook long, they will brown up and cook further in the oven.

8. Once the mushrooms are golden brown, add the wine, garlic, and thyme
I’ve tried this recipe with both red and white wine – both works. You can also use rosemary instead of thyme if you prefer.

9. Coat the muffin tray with cooking oil
Brush a bit of cooking oil in each of the muffin holes. If you’re using a non-stick tray or silicon molds, omit this step.

10. Cut the puff pastry in 9 equal squares and place one in each muffin hole
Don’t spend time on molding the pastry nicely in – they will look nice regardless.

11. Spread out the mushroom and caramelized onion equally for each tartlet
Don’t mix the mushroom and caramelized onion in together – just sprinkle the onion on top. This will serve both as decoration and allow the onion to cook and crust a bit in the oven.

12. Whip the eggs lightly and add a bit to each tartlet while making sure the puff pastry is covered well by the egg
The eggs can be omitted, but they help give a nice shine to the puff pastry, keep it less dry and hold the whole tartlet a bit better together.

13. Bake at 180 degrees celsius for 25 minutes
Or until the puff pastry is baked and golden.

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