Step by step recipe:
- 20 min.
Boiling the langoustinesBoil the langoustiens for 30 seconds in boiling salted water, then cool under running cold water.
Shell them and set aside the tails. Keep half the heads for making the fumet.
- 5 min.
- 2 min.
- 1 min.Add the langoustine heads...
- 2 min.... and crush briefly with the end of a rolling pin, for example.
- 1 min.
- 5 min.Bring to the boil, then turn down the heat to its lowest setting and leave to reduce by half.
This simmering will create the "fumet", as the liquids (water and wine) mingle with the flavours of the bouquet garni and langoustine heads.
- 40 min.
The vegetable brunoiseWhile the fumet is reducing, rinse and peel 2 carrots and 3 turnips, then dice very small ("fine brunoise").
Rinse the courgette and cut the part with the green skin into tiny dice (you can use the leftover courgette in another recipe).
I have to admit, this is a long, arduous task!
- 5 min.Bring a large saucepan of salted water to the boil.
Immerse a fine metal strainer, which will enable you to remove the vegetables quickly.
- 1 min.Toss the diced courgettes into the water, wait until the pan comes back to the boil, then remove them immediately by simply lifting out the strainer.
- 1 min.Cool the diced courgettes under running cold water to stop the cooking...
- 2 min....drain thoroughly, then tip out onto absorbant paper to wait.
- 5 min.Do the same with the carrots and turnips, which can be cooked together, and for 30 seconds longer than the courgettes.
Note: Don't throw this cooking water away - it is now worth keeping.
- 4 min.
- 3 min.
The gratin cream sauceLet's go back to the fumet, which by now should be reduced by half. Strain into a bowl and discard everything but the liquid.
- 2 min.Pour this back into the pan (after rinsing out), but be careful to keep back the dregs of the fumet which will be full of sand and should be discarded.
- 8 min.Put the fumet back on medium heat and leave to reduce by half again.
- 3 min.
- 2 min.
- 4 min.
Assembling the gratinPreheat the oven to 390°F (200°C).
Butter a gratin dish and spread the mixed diced vegetables in an even layer.
- 2 min.Arrange the sautéed langoustine tails on top.
- 2 min.Pour the sauce over.
- 15 min.
Cooking and servingBake for about 15 minutes, until the top is nicely browned (finish under the grill if necessary).
- Best served plated up (on hot plates): try to keep the langoustines on top and the vegetables underneath.
Remarks:As I was saying, this recipe takes a long time, but much of it can be prepared in advance. Only the assembly of the gratin and final cooking need to be done just before serving.
You will see that in step 19 the cream is not reduced, but thickened with cornflour instead. This is to keep a decent quantity of sauce without it being too liquid, otherwise it would run into the bottom of the dish.
If you are happy with the idea, you can dispense with boiling the langoustines in salated water in step 1 and shell them raw before the sauté stage (step 14).
To simplify the recipe, just slice the vegetables thinly instead of cutting into brunoise dice.