Lemon baked Dover Sole with Potatoes

• 2 dover sole fillets
• 250g baby potatoes, thinly sliced
• 2 medium leeks, thinly sliced into ¼  thick rings
• 2 tsp olive oil
• ⅛ tsp salt and pepper
• zest from ½ a lemon
• 1 tsp olive oil 
• pinch salt and pepper
• zest from other ½ half a lemon

Dill Oil:

• 2 tbsp fresh dill, chopped
• 2 tbsp olive oil
• 1 tbsp lemon juice
• ⅛ tsp salt