HEAT oven to 400ºF.
PRESS pastry onto bottom and up side of 9-inch pie plate sprayed with cooking spray; trim edge.
HEAT oil in large skillet on medium-high heat. Add peppers; cook and stir 5 min. or until crisp-tender. Stir in spinach and tomatoes; cook 1 min. Spoon into crust; top with cheese and basil.
WHISK remaining ingredients until blended; pour over ingredients in pie plate.
BAKE 30 min. or until knife inserted in center comes out clean. Let stand 10 min. before cutting to serve.