How much to cook asp?

How to cook asp in white sauce

Products
Asp - 600 grams
Fish broth - 500-700 milliliters
Bechamel sauce - 80 milliliters
Lemon - half
Celery root - 60 grams
Leeks - 100 grams
Butter - 50 grams
Salt - half a teaspoon
Pepper to taste

How to cook asp in white sauce
1. Wash the ash, peel the scales.
2. Remove the head, tail, fins from the asp.
3. Make an incision in the abdomen, gut the asp.
4. Re-wash the peeled asp inside and out, dry with a napkin.
5. Cut the asp into medium-sized portions.
6. Wash the leeks and celery, cut into half rings.
7. Put chopped leek and celery on the bottom of a deep saucepan, and on top - pieces of asp.
8. Pour the asp with fish broth, cover the saucepan with a lid.
9. Place the casserole dish over medium heat, let the broth boil, cook for 10-15 minutes.
10. Remove the saucepan from heat, strain the broth into a cup.
11. Transfer the fish to a dish.
12. Pour the broth back into the saucepan, cook for another 10-15 minutes without a lid, so that its volume is halved.
13. Pour the bechamel sauce into the broth, warm up, but do not bring to a boil.
14. Pour the resulting sauce into a bowl.
15. Melt the butter in the microwave or in a skillet over low heat.
16. Squeeze the juice from half a lemon with your hands.
17. Pour lemon juice, butter into a bowl with sauce, mix.
18. Serve the white sauce to the boiled asp.