Scrub and de-beard the mussels. Discard any which are broken. If there are any which are open give them a sharp tap on the work surface. Any which remain open are dead and must be discarded. Cook the pasta in boiling salted water until al dente and drain. Now pour the nage into a wide shallow pan and boil until reduced by half. Add the mixed vegetables and mussels and simmer for 3-4 minutes, until the mussels are opened up. Then add the olive oil, tomato concasses, chopped herbs and lasagne sheets. Season with salt and pepper, add the lemon juice and warm through for 30 seconds or so. Divide between shallow serving bowls giving everybody 2 sheets of pasta and an equal amount of mussels and sauce. Take a bit of care here and youll have quite an impressive assortment of colours and textures. Decorate with sprigs of chervil. Per serving: 424 Calories (kcal); 20g Total Fat; (42% calories from fat); 45g Protein; 14g Carbohydrate; 105mg Cholesterol; 1073mg Sodium Food Exchanges: 0 Grain(Starch); 6 1/2 Lean Meat; 0 Vegetable; 0 Fruit; 2 1/2 Fat; 0 Other Carbohydrates Converted by MM_Buster v2.0n.