Preheat the oven to 200°C, 180°C Fan, Gas Mark
2. Place the sweet potato and red onions into a large ovenproof dish. Add 1 tablespoons of oil, the smoked paprika and garlic. Season and gently toss together.
Roast for 25-30 minutes tossing the vegetables occasionally, until tender and caramelised. Remove, cover, and set aside.
For the kale salad, place the kale in a large salad bowl and 'massage' the kale or cavolo nero leaves with lemon juice and a pinch of salt. Add the tomatoes, cucumber and 2 tsp oil. Set aside.
Heat a non-stick frying pan over moderate heat until hot. Brush the steaks with the remaining oil and season on both sides. Cook the steaks for 1-2 minutes on each side (for medium) and allow to rest for 1-2 minutes before slicing.
Serve the steak tossed through with the warm smoky sweet potatoes and kale salad and garnish with the lemon wedges.