1. Preheat oven to 400 degrees. 
  2. Thinly slice the tomatoes and seed them. Place the seeded slices on 2 layers of paper towels and let tomatoes drain while you are preparing the crust. Gently press a layer of paper towels on top to absorb juices. Flip tomatoes and repeat. Be sure to drain the tomatoes well, otherwise your tart will be soggy. 
  3. Roll the puff pastry dough into a 12 x 12 square and trim edges to fit into a 10-inch tart pan. 
  4. Place dough in tart pan and score with a fork all round dough before baking to keep crust even. Blind bake the crust in preheated oven for 20 minutes. Remove and let cool for 10 minutes. 
  5. Top cooled crust with pesto and spread evenly to cover crust. Place Kerrygold mild cheddar slices on top to cover the pesto. Place tomatoes on top of cheese in concentric circles and bake for 10  15 minutes or until cheese is melted. 
  6. Garnish with fresh basil and serve.