1. put the flesh of 2 avocados through a food mill and liquefy them in 1 liter (4 cups) milk;
2. sauté one minced onion in a saucepan until lightly colored; add 3 tbsp. flour and the milk-avocado mixture, as if making a béchamel sauce; 
3. simmer until thickened; 
4. chill and serve with toasted baguette slices. 

Crab-Stuffed Avocado

1. scoop out the flesh of an avocado with a spoon; dice it; 
2. make the dressing with 125 ml (1/2 cup) mayonnaise, juice of half a lemon, 1 tsp. Worcestershire sauce and Tabasco to taste; 
3. add 1 can of crabmeat and some chopped celery and shallot; 
4. combine everything; fill the hollowed out avocado halves and serve immediately since avocado tends to darken quickly.