Place the cubed sweet potatoes and olive oil in a bowl and mix well until the potatoes are coated in the oil.
Put the coated potatoes on a roasting tray and roast in the oven for about 25 to 30 minutes until tender.
Whilst the potatoes are cooking gently heat a small pan until hot then add the chorizo and cook, stirring until the chorizo is crisp but not burnt. Remove it with a slotted spoon and drain on a piece of kitchen paper.
Place all the dressing ingredients in a jar and shake well.
When the potatoes are cooked mix them in a large bowl with the cooked chorizo, sesame seeds, baby spinach and dressing.