Preheat oven 220°C/200°C fan forced. Line a baking tray with baking paper. Cut sweet potato in half lengthways. Lay cut-side up on the lined tray. Spray with olive oil and season. Bake for 35-40 minutes or until softened and lightly golden.
COOK THE MUSHROOMS
Meanwhile, heat the oil in a large non-stick frying pan over medium heat. Add the onion and cook, stirring, for 3-5 minutes or until softened. Add the mushroom and garlic, and cook, stirring, for a further 4-5 minutes or until softened. Stir in the kale for 2 minutes or until just wilted. Season well. Fold through half the pesto.
MAKE THE STUFFING
Use a spoon to scoop out the soft sweet potato flesh, leaving a 5mm-thick shell. Add the sweet potato flesh and half the cheese to the mushroom mixture. Gently toss to combine. Spoon the mushroom mixture into the sweet potato shells, piling the filling high.
BAKE AND SERVE
Dollop the remaining pesto over the potatoes. Sprinkle with the walnuts and remaining cheese. Spray lightly with oil. Bake for 15 minutes or until the cheese is melted and the potatoes are golden. Sprinkle with the micro herbs.
