Preheat oven to 180ºC (355ºF). Place the eggs, sour cream, salt and pepper in a bowl and whisk to combine. Use an 8½cm-round cookie cutter to cut out 12 rounds of pastry. Line 12 x ¼ cup-capacity (125ml) lightly greased muffin tins with the pastry. Pour in the egg mixture and bake for 15 minutes or until the pastry is golden and the egg is set (the egg will puff up in the oven but reduce on cooling). Place the tomato, basil, vinegar and oil in a bowl and toss to combine. Top each tart with the tomato mixture to serve. Makes 12.