From Saveur August/Sept. 2015 issue
2# cherry tomatoes, halved
1/2 medium red onion, thinly slices length-wise
1/4 cup olive oil
3Tbsp. red wine vinegar
Kosher salt
1# red or yellow Heirloom tomatoes, cored and sliced cross-wise
Fresh black pepper
1 cup loosely packed mint leaves, torn into fire-sized pieces
sea salt to taste
1. In a large bow, toss the cherry tomatoes with he red onion, olive oil, and vinegar
Season with salt and let stand, stirring every 5 minutes, to marry flavors, about 20 minutes.
2. Arrange the heirloom tomato slices on a serving patter and then spoon the cherry tomatoes and dressing over the top. Season with pepper and sprinkle with the mint leaves and sea salt before serving.