Place mussels, butter and wine in large saucepan.
Add water and shallot.
Cover and bring to boil; cook until shells open.
Remove saucepan from heat.
Separate mussels from shells, pouring juices back into saucepan.
Set mussels aside and discard shells.
Strain cooking liquid from mussels through cheesecloth into clean saucepan.
Bring to boil and continue cooking 4 to 5 minutes.
Mix in white sauce and paprika; season well.
Cook 3 to 4 minutes over low heat.
Stir in 1/2 cup (125 ml) cheese; continue cooking sauce 1 minute over low heat.
Remove saucepan from heat and add mussels; mix well.
Spoon into scallop shells and top with remaining cheese.
Broil in oven until golden brown.