Season the flour with salt and freshly ground black pepper then dredge the sole fillets in the flour.
Add 40g/1 oz of the butter and half the sole fillets and fry for 1-1 minutes on each side, or until golden-brown.
Add the sole fillets and poach until cooked through, about 8 minutes.
Remove the toothpicks from the sole fillets and place 2 of the rolls over the sauce on each plate.
In the meantime, the sole fillets are rolled and secured with a toothpick.
Place 1 sole fillet on each of 4 plates, spoon the sauce over and sprinkle with the scallions.
Place 1 sole fillet in the center of each of 4 plates.
It took nearly an hour to fix the sole fillets in position.
Repeat with the remaining sole fillet and asparagus, then place onto a sheet of aluminium foil inside a steamer.
To serve, place the steamed sole fillets onto a serving plate, pour over the sauce and garnish with the chilli half.