Step 1: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
Step 2: In a medium bowl, combine the full-fat plain Greek yogurt and the large egg. Whisk them together until smooth and well incorporated.
Step 3: Add the psyllium husk powder, baking powder (if using), and salt (if using) to the yogurt-egg mixture. Mix vigorously with a spoon or spatula until a thick dough forms. The psyllium husk will rapidly absorb moisture, so work quickly.
Step 4: Let the dough rest for 5-10 minutes. This allows the psyllium husk to fully hydrate and the dough to firm up, making it easier to handle.
Step 5: Divide the dough into 6 equal portions. With slightly wet hands (this prevents sticking), roll each portion into a ball and then flatten it slightly into a disc or an oval shape, about 1/2 inch thick, resembling a small roll or flatbread.
Step 6: Place the shaped dough pieces onto the prepared baking sheet.
Step 7: Bake for 20-25 minutes, or until the bread is golden brown on the outside and cooked through. The internal temperature should reach about 200°F (93°C) if you're checking with a thermometer.
Step 8: Remove from the oven and let cool slightly on a wire rack before serving. This bread is best enjoyed fresh but can be stored.