Place the filet of sole in the flour to coat them lightly and set aside.
Heat a sauté pan over medium heat. Drizzle some olive oil and place the potatoes.
Sauté for 2 minutes until coloured and warmed through then if the sauté pan is wide enough add the sole filet, flesh side down. Cook for a further 2-3 minutes, turning the fish over once. Season the fish with salt and pepper. Add the butter and tomato pieces and sage leaves.
Baste the fish with the foaming butter for 2-3 minutes. Squeeze some lemon juice and remove from the heat.
Serve the sole fillets with the potato and tomatoes.