In a medium saucepan, bring the broth to a boil; reduce the heat and keep at a simmer.
Place another medium saucepan over medium heat 30 seconds; heat the oil 30 seconds more.
Add the onion; cook, stirring frequently, 2 minutes, until softened.
Stir in the rice; cook, stirring constantly, 1 minute.
Add the wine and 1/2 cup of the broth; cook, stirring constantly, until all the liquid is absorbed.
Continue adding the broth, 1/2 cup at a time, stirring constantly until each addition is absorbed before adding more broth, until all but 1 cup of the broth has been used.
Add the remaining cup of broth, the shrimp and scallops; cook, stirring constantly, 6-8 minutes, until all the liquid is absorbed, the shrimp are pink, the scallops are just opaque and the mixture is creamy.
Remove from the heat; stir in the cheese, thyme and pepper.