Preheat the oven to 390°F (200°C).
Peel and slice the sweet potatoes and add to a bowl with the olive oil, salt, pepper, onion powder, garlic powder, smoked paprika and cayenne pepper and toss together so that all the pieces of sweet potato are lightly coated.
Transfer to a parchment lined baking tray and spread them out evenly.
Place into the oven to bake for 30 minutes.
While the sweet potato is baking, prepare the rest of your salad ingredients.
Slice the olives and the sun dried tomatoes, chop the cilantro and add to a bowl with the black beans and a sprinkle of salt and pepper. Toss together.
Wash your mixed lettuce greens and peel and slice your avocado.
When the sweet potatoes are cooked assemble the plates of salad with salad greens on the bottom, then the black bean and cilantro mix, then sweet potato slices, avocado slices and top with a drizzle of tahini dressing.
Alternatively, you can place it all in a big salad bowl, but be careful when you dish up so that you don't break up the sweet potato.