Preheat oven to 200°C (convention)/180°C (fan-forced/convection). Line a rimmed baking sheet with baking paper.
Place all ingredients for the sweet potato in a medium bowl and toss to coat evenly. Spread sweet potato on the prepared sheet and roast in the oven for 20-25 minutes until starting to turn golden. Remove from the oven and set aside.
Heat 2 tablespoons oil in a medium wok or frying pan. Add the onion and sauté for a few minutes. Reduce heat and cook until onions are caramelized. Add the chickpeas, harissa and lemon juice. Mix well and cook for a couple of minutes until coated and heated thoroughly. Remove from heat and stir through the sweet potato, parsley and coriander. Check for seasoning and adjust with sea salt flakes and freshly ground black pepper.
Arrange spinach leaves in serving bowls, top with the warm sweet potato and chickpea salad. Garnish with almonds and serve with lemon wedges.