Preheat the oven to 400 degrees.
In a food processor, combine 3/4 cup of the basil reserving a 1/4 cup to garnish, walnuts, lemon juice, garlic, nutritional yeast, 1 tbsp olive oil and 1 tsp salt and pulse until blended.
Gently roll out the pastry on a counter that has been dusted with the 1 tbsp of flour; to a 10 x 12 inch rectangle. Cut the pastry into 6 equal rectangles. Gently score a border around the edge of each rectangle and poke the middle 3 to 4 times with a fork.
Spread some pesto inside each rectangle, avoiding the borders. Place a slice of tomato on each rectangle and lightly brush the tomato with last tablespoon of olive oil and sprinkle with remaining salt and pepper. Bake for 17 to 20, or until the crust is puffy and golden.
Cool the tarts for 5 minutes, then sprinkle with the reserved basil leaves. Enjoy!