Boil the water for the rooibos tea, then remove from heat and steep the tea bags for 10 minutes. Then refrigerate to cool until ready to serve.
Prepare all ingredients as listed above.
Preheat the grill on medium heat.
In a small bowl, mash the avocado, mix in mayonnaise, lime juice, cilantro, and dill until combined.
Season the salmon with pepper, then drizzle with olive oil. Grill the salmon on both sides until cooked through, to an internal temperature of 145°F (63°C). Then squeeze lime over top.
Toast the buns on the grill, cut side down, if preferred.
Assemble the Sandwiches: Spread the mayo inside the bun, layer with shredded cabbage, tomato slices, grilled salmon, cilantro, and feta slices.
Serve with chips, pickle, and rooibos iced tea.