Mushrooms stuffed with salmon with thermomix

Preparation

1. We start by cleaning the mushrooms very well and making sure to remove all the dirt very well. Once clean, cut them from the trunk, leaving the upper part as if it were a bowl. Reserve.
2. In the glass of the thermomix add the trunks of the mushrooms together with the onion cut into pieces, program.
3. 5 seconds / Speed ​​5.
4. Once the onion and the mushroom trunks have been chopped, lower the remains that have adhered to the walls of the Thermomix bowl with the help of the spatula and then add the measure of butter, program again.
5. 5 minutes / Temperature 100° / Speed ​​2.
6. To continue, add the salmon cut into squares or small strips and program.
7. 1 minute / Temperature 100° / Reverse spin / Speed ​​2.
8. Once the salmon is cooked, proceed to add the milk, the remaining 20 grams of butter, the cornstarch or flour, the nutmeg and the salt and pepper (or alternatively, the ½ tablet of vegetable broth), program.
9. 8 minutes / Temperature 100° / Reverse spin / Speed ​​2.
10. You can check the thickness of the salmon bechamel sauce through the mouth of the lid of the thermomix container, since it may thicken before the suggested time or, on the contrary, it may require a little more time.
11. Preheat the oven to 180°C.
12. Once the salmon bechamel sauce is ready, fill each mushroom cap with the sauce, place each one on a tray suitable for the oven, preferably with a little olive oil or non-stick paper.
13. When they are all stuffed, add a little gratin cheese on top of each stuffed mushroom and bake at 180°C for 10 minutes or until the cheese is gratin.