To prepare dressing, combine first 9 ingredients in a small food processor or blender; process 30 seconds or until pureed, scraping sides of bowl occasionally. Cover and chill.
To prepare salad, slice each tomato crosswise into 4 equal slices (about 1/2 inch thick). Place 1 tomato slice on each of 4 salad plates; sprinkle slices evenly with 1/4 teaspoon salt. Top each serving with a few onion pieces and about 1 tablespoon avocado. Repeat layers 3 times, ending with avocado. Drizzle 2 tablespoons dressing over each serving; sprinkle with black pepper, if desired.
Can't get enough of Heirloom tomatoes this time of year and anything with cilantro works for me!! I had no buttermilk on hand so I made my own with 1 tsp white wine vinegar and 1/3 cup fat free milk. This was a beautiful salad - great presentation!! I served with the Corriander-Crusted Tuna with Black Been Salsa. This will definitely become a regular!
FANTASTIC!!! Tastes great, fairly easy to prepare, and it looks like something you'd get at a high-end restaurant. Of course as soon as you cut into it, the thing will become a bit messier, but it sure is gorgeous sitting on a salad plate. My family doesn't care for cilantro so I subbed in flat-leaf parsley and the results were wonderful. We used a mix of Cherokee purples, early girl, and mortage lifters for the salad and I think the quality of this dish will be directly proportional to the quality of your tomatoes. I'd recommend assembling right before serving so that the avocado doesn't brown.
This was AMAZING - I bought heirloom tomatoes from the farmer's market and thought this recipe was just delicious. It's great for guests and simple enough to make for a weekday dinner. Highly recommended as is - no alterations necessary!