In skillet, melt Gay Lea Salted Butter over medium heat.  Add onion, garlic, basil, salt, oregano and pepper; cook, stirring for 5 minutes.  Remove from heat; let cool slightly.  Stir in Gay Lea Sour Cream, whipping cream, eggs and 2/3 of the cheese.

Meanwhile, on lightly floured work surface, roll out entire piece of pastry to 15 x 11-inch rectangle.  Fit into 13 x 9-inch baking pan, making a 2-inch border up sides.  With tines of fork, prick pastry all over.  Line pastry with large piece of parchment paper or aluminum foil.  Fill with pie weights or rice.  Bake in centre of preheated 400 F (200 C) oven for 15 minutes.  Remove weights and parchment paper.

Spread filling evenly over pastry.  Arrange tomatoes over filling in single layer.  Sprinkle with remaining cheese.  Bake for 25 to 30 minutes or until filling is puffed and set.  Let stand for 10 minutes before cutting into squares.