Place lettuce, mango, strawberries/cranberries, and red onion in a bowl. Right before serving, add nuts, avocado, and dressing. Toss lightly.

Pulse all ingredients in a food processor or use a hand blender for 30 seconds. Add up to 2 tablespoons water if it’s too thick. (You can also make this in a bowl, using a whisk, if necessary.)