Noodlesalad with tuna mayonnaise

ingredients for 15 persons:          
500 g noodles
salt          
pepper          
mayonnaise for salad (40% fat)          
250 g yoghurt
300 ml cream
200 ml milk
60 g capers      
2 cans with tuna
2 small tins peas 
500 g red onions
1 kg tomatoes

preparation: Cook noodles in salt water "al dente".
Chop onions and tomatoes. Mix noodles, onions, tomatoes
and peas. Make a purree of tuna and mayonnaise using 
a mixer. Stir cream, yoghurt and milk under the tuna 
mayonnaise. Season with salt and pepper and spoon 
the sauce over the salad.