1. Place a rack in the middle of the oven and preheat to 425 degrees F.
2. Make the “caviar”. Place the eggplant, whole, on a baking sheet and bake for 45 minutes, flipping the eggplant from side to side once or twice, until it is very soft, collapsed looking, and the skin appears wrinkled. Remove from the oven, let it cool slightly, and peel Cut off both ends. Cut the peeled eggplant in half and put it back on the baking sheet. Use a large plate to press down on the eggplant to remove all the juices; discard the juice.
3. Place the drained eggplant in a food processor or blender and blend until almost pureed.
4. In a medium-large bowl, crush the garlic with the salt, using the back of a spoon to create a mash. Add the oil and pepper and stir well. Add the yogurt and lemon juice and then stir in the pureed eggplant. Taste for seasoning.
5. Make the tomato-mint salad: In a medium bowl, mix together the tomatoes, scallions, oil, mint, and salt and pepper to taste. Taste for seasoning. The eggplant and the tomato salad can be covered and refrigerated for a day ahead of time.
6. Put the eggplant puree on a medium-large serving plate and surround the outside edges with the tomato salad. Garnish with the fresh mint leaves.