Peel and cut the potatoes in half and boil in salted water until tender (approx 25 minutes). Drain and mash the potatoes, adding some butter and cream, a little at a time. Season with salt and pepper and keep mashing until the potatoes are light and fluffy.
To fry the sea bass, lightly flour the skin side of the fillet and season with salt and pepper. Heat a pan, add a knob of butter and once all the butter has melted in the pan and started to sizzle, add the sea bass flour side down and cook for 2 - 3 minutes. Turn the sea bass over on the other side a cook for a further 3 minutes.
Add a little olive oil, lemon juice, spring onions and chilli to the pan that your fish was in and cook, stirring all the time for about 1 minute, taking care not to overheat the pan.
Spoon the creamed mashed potato onto the centre of the plate. Sit the sea bass on top of the potatoes and drizzle the chilli and spring onion mix all around the dish.