In a large bowl combine 1 ½ cups whole wheat flour, ½ cup all-purpose flour, undissolved yeast, sugar, and salt. Add warm water and oil, mix until well blended, about 1 minute.
Gradually add remaining flour to make a soft dough. The dough should form a ball and be slightly sticky. Knead on a floured surface, added more flour as needed to reduce sticking. Knead until smooth and elastic, about 4 minutes.
Allow dough to rest for 10 minutes covered with a kitchen towel. After the dough rests cut into 8 even portions, shape into balls, transfer to a sheet tray and lightly cover with a kitchen towel. Meanwhile, make the pesto sauce while dough is resting.
Add spinach, basil, yogurt, garlic, olive oil, salt and pepper to a blender or food processor. Blend until a smooth puree is achieved, about 15 to 30 seconds.
Grease a large baking sheet with oil. You may need 2 sheets. Working with one piece of dough at a time, flatten into a circle and roll out to 7 or 8 inches in diameter. Add one tablespoon of pesto sauce, spread out using a spoon, leaving a ¾-inch border around the edges.
Cut cheddar slices in half in the shape of a triangle.
On half of the sauced dough, layer as follows: Add 1 slice of cut cheddar cheese, 2 slices of turkey, a few spinach leaves, 1 slice of cheddar cheese, 2 slices of turkey and 1 tablespoon tomatoes. Season with salt and pepper if desired. Make sure to layer the ingredients as flat as possible and leaving a border on the edge of the dough, so it’s easy to close.
Fold over one side of the dough that does not have the filling and press edges firmly together until sealed to create a half moon shape. The most important thing is to make sure the edges are sealed. Repeat with the remaining balls of dough. Transfer formed pocket sandwiches to the oiled sheet tray. I fit about 6 to a tray, but you can split up four on each if needed.
Lightly brush olive oil over the top of each pocket sandwich, sprinkle with salt and pepper. Make 3 small slits in the center of the sandwiches.
Bake at 425°F for 14 to 16 minutes in the center of the oven, or until the tops and bottoms are lightly golden brown and edges are lightly crisp. Bake longer or shorter as needed.
Refrigerated: Microwave 1 minute or until warm in the center. Or heat at 425°F on a sheet tray in the center of the oven for 5 to 7 minutes until warmed through and crisp.
Frozen: Microwave for 1 min 30 more seconds or until warm in the center. You can then transfer to a 425°F oven on a sheet tray in the center of the oven for 5 minutes, or until crisp.