Preheat oven to 375°F. Coat the bottom and sides of a full size hotel pan with some of the olive oil.
In a large sauté pan, cook onion in remaining olive oil over medium heat until translucent. Add garlic and dried herbs and cook for one minute. Add tomato paste and cook until it turns bright orange, then add honey, lemon zest, chopped tomatoes, salt and pepper. Cover and simmer for 10 minutes stirring occasionally. Add olives, simmer 15 minutes.
Slice potatoes into 1/4 to 1/4" thick slices. Place in a large bowl with the yogurt, toss and set aside until ready to use.
Combine ricotta cheese, Parmesan, cheddar/mozzarella blend and parsley in a bowl.
Arrange a layer of potatoes in the prepared pan, cover with a layer of the tomato mixture and top with a layer of cheese. Layer potatoes and tomato mixture and again top with cheese.
Bake covered with foil 40 minutes. Remove foil and bake gratin for 20 to 30 minutes more, or until potatoes are very tender. Remove and sprinkle with additional chopped parsley if desired. Cut into 24 portions.
To serve: place flatbread on a plate. Top with 3 oz mixed greens drizzled with I to 2 oz vinaigrette. Place potato gratin in the middle of the greens. Garnish with sliced fresh vegetables or lives if desired
For individual servings, Chef Thompson makes these in 1 cup ramekins and tops the gratin with assorted roasted and grilled vegetables before the final layer of cheese.