Marinate tempeh: Combine broth, maple syrup, apple cider vinegar, tamari, paprika, salt and liquid smoke in an 8x8-inch baking dish. Lay tempeh in a single layer, being sure to cover with marinade. Refrigerate for 30 minutes to overnight.
Make pesto by combining all pesto ingredients, except the oil and feta, in a food processor and pulsing until combined. Slowly pour in olive oil while food processor is running. Once combined, fold in the feta.
Remove tempeh from marinade, reserve marinade and pat tempeh dry. In a large pan over medium, heat ghee or coconut oil. Cook tempeh slices for about 4 minutes per side. If pan gets too dry, add a tablespoon or two of reserved marinade. Set cooked tempeh aside.
To build the TLATs, spread a layer of sun-dried tomato pesto on one slice of bread and top with a handful of arugula. Place a few slices of cooked tempeh over the greens, and top with avocado slices. Spread another piece of bread with pesto, and place pesto-side down on top of avocado.