Heat fish broth and next 5 ingredients in a deep skillet over medium heat until simmering. Reduce heat to medium-low, and add fillets. Cover and poach 5 to 8 minutes or until fish is opaque and flakes with a fork. Transfer to serving plates. Spoon shallots and rosemary leaves over fish, and drizzle with olive oil. Garnish, if desired.
Pour: There will be plenty of wine left over from poaching to serve during dinner, so be sure to buy a wine you'll enjoy drinking. For mild fish such as cod, haddock, or sole, try Valley of the Moon Pinot Blanc—a crisp white that pairs nicely with the shallots and rosemary. With oilier fish such as sablefish, pompano, or mahi mahi, try Kenwood Sonoma Chardonnay for just the right balance of acidity.