Thinly slice the onion.
Place the sweet potatoes and onion on a baking sheet.
Add olive oil, salt and pepper to taste and bake at 200°C for 20 minutes.
Whisk the mustard with the honey, vinegar and spice.
Add the olive oil in slow stream and whisk until completely mixed.
Pour the dressing on the warm sweet potatoes.
Add the cranberries and coarsely cut parsley.
Stir gently and add salt and pepper to taste.
Serve with feta crumbled into large pieces.
