I wish I'd had romaine lettuce on hand; the spinach was one too many flavors, and the dish was kind of muddy as a result. But I really like how the mousse turned out. The fatal flaw: I didn't get the avocado quite smooth enough, mostly because I was lazy and mushed it up with a fork for awhile instead of using a food processor or immersion blender. Nobody likes a sporadic chunk of avocado in their mousse! I've got the leftover mousse in the freezer and plan to sprinkle it with cocoa powder and a little sugar and eat it for dessert. Maybe upon my next avocado acquisition, I'll beat some honey and cocoa (or melted chocolate... I wonder if that would work) into the avocado component, freeze the finished product for a couple hours, and top it with shredded chocolate before eating it. If only I'd thought of that before eating the other one for lunch.
1 large avocado
juice of 1/2 small lemon
1 tbsp milk
2 egg whites
pinch each salt, pepper, and sugar
Mash, whip, and otherwise pulverize the avocado with the lemon juice and salt, pepper, and sugar until the mixture is smooth. Beat the egg whites until stiff. Stir the milk and a spoonful of the egg whites into the avocado mixture to lighten it, then gently fold in the rest of the whites until just incorporated.
*This stuff has almost exactly the consistency of mayonnaise, but it's much more healthful. I'm keeping this in mind for future recipes.