How to Make It
Preheat the oven to 275°. Prepare a bowl of ice water. In a medium pot of boiling water, blanch the tomatoes just until the skins loosen, about 30 seconds. Using a slotted spoon, transfer the tomatoes to the ice water to cool. Drain and peel the tomatoes, pat dry and halve crosswise.
Arrange the tomatoes, cut side up, on a nonstick baking sheet and drizzle with 2 tablespoons of the olive oil. Sprinkle with the chopped thyme and season with salt and pepper. Roast for about 2 1/2 hours, or until the tomatoes are very tender and slightly shrunken. Transfer the tomatoes to a plate and let cool.
Meanwhile, spread the brioche cubes on a small baking sheet and toast for about 15 minutes, or until golden and crisp. Let the croutons cool.
In a small bowl, whisk the mayonnaise, crème fraîche and buttermilk until smooth. Add the lemon juice, parsley, mint and 1 tablespoon of the chives and season with salt and pepper. Refrigerate until chilled.
In a medium skillet, cook the bacon over moderate heat, stirring occasionally, until browned and slightly crisp, 8 to 10 minutes. Transfer to paper towels to drain.
Put each iceberg wedge on a plate, add a tomato half and drizzle with the remaining 2 tablespoons of olive oil. Scatter the croutons and bacon on top. Garnish with the remaining 2 tablespoons of chives and serve, passing the buttermilk dressing at the table.