Cook fettuccine in large pot of boiling salted water just until al dente, 6 to
8 minutes; drain well. Return to dry pot.
While fettuccine is cooking, place butter and cream in heavy skillet over medium-low
heat. Cook, stirring constantly, until blended and mixture bubbles for 2 minutes.
Stir in salt, pepper and nutmeg. Remove from heat.
Gradually stir in Parmesan cheese until thoroughly blended and fairly smooth.
Return skillet briefly to heat if necessary to completely blend cheese, but don't
let sauce bubble or cheese will become lumpy and tough. Pour sauce over fettuccine
in pot. Place over low heat. Stir and toss with 2 forks until sauce is slightly
thickened and fettuccine evenly coated, 2 to 3 minutes.