Cook linguine according to package directions. Meanwhile, in a large nonstick skillet over medium heat, cook onions and garlic in butter for 1 minute. Stir in seafood seasoning; cook 1 minute longer. Add shrimp; cook for 3-4 mintues until shrimp are pink. Remove and keep warm.
Combine flour and cream util smooth; stir into skillet, scarping up any browned bits. Bring to a gentle boil and stir for 2 minutes or until thickened. Reduce heat; stir in cheese until just melted. Return shrimp to the pan and heat through.
Drain pasta. Either combine shrimp mixture with pasta OR top pasta with shrimp mixture.