Crust:
1 cup all-purpose flour
1 teaspoon sugar
1/2 teaspoon salt
2 tablespoons unsalted butter, chilled and cut into small pieces
2 tablespoons vegetable shortening, chilled
3 1/2-4 tablespoons cold water
Filling:
1 tablespoon olive oil
1 medium Vidalia or other sweet onion, chopped, about 1 cup
1 teaspoon chopped fresh thyme
1/4 teaspoon salt
1/4 cup sugar
4 teaspoons sherry vinegar
4 1/2 cups assorted color cherry tomatoes
Mayo:
1/2 cup mayonnaise
2 oil packed anchovy fillets, drained and mashed into a paste
1/2 teaspoon grated fresh lemon zest