To make the dough, in a large mixing bowl add the yeast, water, and agave. Whisk together and let sit for a few minutes. You'll see some bubbling activity which means the yeast is ready to go. Add the salt and olive oil and whisk one more time. Next, add the flour. Using a mixing spoon, stir for a minute or two, until well combined.
Dust a cutting board or clean surface with a sprinkling of flour and transfer the dough. Knead the dough for about 5 minutes, until the texture becomes smooth and elastic. Initially, the dough might be sticky, so you can use a bench scraper to help you release it if need be. Mound into a ball and transfer to a clean, greased bowl. Rotate the dough around so that it is lightly coated all around. Cover with a towel or plastic wrap and set in a warm spot. Let sit for about 1 hour or until doubled in size.
When ready to grill, rub a cutting board or clean surface with vegetable oil to prevent sticking. Transfer the dough and cut into 6 even pieces. Using your fingers, press each piece into a large oval shape, about 6 inches long and 4 inches wide. Transfer to a greased baking sheet.
For the tempeh, combine the rosemary, oregano, nutritional yeast, rice vinegar, dijon mustard, agave or maple syrup, tamari or soy sauce, olive oil, salt, black pepper and water to a large cast-iron skillet. Mix well. Add the tempeh and red onions and gently mix. Set aside and get the grill ready!
To prepare the grill, fill a small bowl with vegetable oil and crumple up a paper towel in a ball. Dunk the paper towel into the bowl and using long tongs, rub the paper towel all over the grill grates. Turn the heat on high and get the temperature to about 600 degrees F. Before grilling, open the lid and rub the oily paper towel over the grill grates once more, in particular where the bread is going to be grilled.
Place the cast iron skillet on one side of the grill and let it cook for about 15 to 20 minutes, mixing with some tongs every so often. Use a sprig of rosemary to glaze each piece with marinade. Once the liquid has evaporated and becomes sticky, the tempeh batons are done. At this point, you can serve as is or transfer directly to the grill to get some charred lines. Just make sure to grease the grill grates thoroughly before doing so to prevent sticking.
While the skillet tempeh and onions are cooking, start making the flatbread. Make sure the grill has been closed and the temperature is closer to 500 degrees F. Open the lid and throw on 3 flatbreads. Close the lid and cook for 1 minute. Open the lid and, using a long spatula or tongs, check the bottom of the bread. If you'd like the charring to be darker, keep it on longer, 20-30 seconds. Flip and close the lid. Cook for an additional minute. Open the lid and check. Once again, if you'd like it to be more charred, continue to cook a little bit longer. Make sure not to overcook the bread as it will get hard! You want it to be soft. Transfer to a platter and cover with a clean towel until ready to plate. Repeat this step with the remaining dough.
Once the bread and tempeh are done, it's time to assemble the flatbreads. Spread a thick coat of yogurt on each piece of bread. Add the tempeh and onions. Next, add the sliced cucumber and fresh herbs. Don't skimp on the herbs! They really make the dish. Squeeze fresh lime juice over top and sprinkle with salt and pepper to finish. Enjoy!