This is one of our favourite salads. Easy to make, can be made ahead, and it's always one of the first buffet dishes to empty.
This dish is an excellent all-around crowd pleaser, buffet staple and picnic basket stuffer. The grape tomatoes and baby bocconcini help keep the ingredients from getting overly soggy, so it looks fresh for some time. It can be made ahead, with the last minute-addition of the basil.
Prepare the dressing first, combining the olive oil, vinegar, juice of one-half of the lemon, the oregano or seasoning and all but a sprinkle of the zest. The remaining zest (for garnish) can be left long and stringy or chopped into fine pieces, as preferred. Adjust oil and vinegar to taste.
Slice the avocado, then cut into chunks and turn gently into a bowl, separating the pieces as best you can without turning them into mush. Gently add the tomato, bocconcini and olives if using. Add dressing while folding mixture gently. Add basil at this point if you are serving right away, but if not, store the salad and the basil separately in the fridge until ready to serve. Garnish with fresh ground pepper, whole basil leaves and reserved lemon zest.
Another delicious version of this salad which passes for Greek Salad, replaces the bocconcini with cubes of feta cheese. The avocado can be replaced by a half-cup rough-chopped onion.