Preheat oven to 450°.
Place potatoes in a saucepan; cover with water. Bring to a boil; cook 15 minutes or until tender. Drain. Return potatoes to pan; add flour, oil, salt, and egg. Mash potato mixture with a potato masher until smooth.
Spread potato mixture into a 9-inch round cake pan coated with cooking spray. Combine seasoning, garlic, and tomatoes; spread evenly over potato mixture. Combine cheeses, and sprinkle over tomato mixture. Bake at 450° for 25 minutes or until golden. Let stand 20 minutes. Cut torta into 4 wedges. Garnish with thyme, if desired.