Preheat the oven to 200°C.
Line a baking sheet with foil.
Cube the sweet potatoes into 1-cm-thick pieces. Toss them with cinnamon on the foil-lined baking sheet. Drizzle with 3 tablespoons of olive oil and season with salt and pepper. Cook for 25 minutes or until tender.
Add 1 tablespoon olive oil, the garlic clove and the mushrooms in a medium-size skillet. Season salt and black pepper and cook ove medium-high heat for about 5-7 minutes until the mushrooms are golden. Stir in the parsley and remove from the heat.
In a small bowl stir flour and water with a spoon, then knead until you get a smooth, non-sticky dough (about 2 minutes). Divide it into 6 pieces. Flour your work surface and roll the dough into a 15-cm-diameter circle.
Heat a non-stick pan, then cook each Taco Shell over high heat, 1 minute each side. Wrap the Shells in a clean dish towel to keep them warm.
Squeeze the juice from the lime onto the avocado slices. Assemble the tacos by filling each shell with avocado’s slices, sweet potatoes and mushrooms.
For further info on how to make the Taco Shells from scratch, read our Quick Flatbread Recipe.