1. Preheat oven to 350°.
2. Place bread in a food processor; pulse 7 times or until coarse crumbs measure about 1 cup. Place on a baking sheet. Bake at 350° for 8 minutes or until toasted. Transfer to a plate; cool.
3. Position oven rack to the top one-third of the oven. Increase oven temperature to 425°.
4. Melt butter in a large nonstick skillet over medium heat. Add fennel and garlic to pan; cook 2 minutes, stirring often. Add broth and salt; cover and cook 5 minutes or until fennel is tender. Uncover and cook 2 minutes or until liquid evaporates. Stir in liqueur; cook 1 minute or until liqueur evaporates. Transfer fennel mixture to a bowl; add breadcrumbs, cheese, fennel fronds, rind, juice, and red pepper. Toss to combine.
5. Arrange oysters in a single layer on a large baking pan. Top each oyster with about 1 tablespoon fennel mixture. Bake at 425° for 10 minutes or until the edges of the oysters begin to curl and the stuffing is lightly browned. Serve immediately.
Wine note: Contrast the rich texture of these oysters with a cold, crisp chablis. A classic partner for oysters, chablis brings out the mineral quality of these prized shellfish while its palate-cleansing acidity nicely slices the butter- and cheese-laced stuffing. William Fevre Chablis Champs Royaux 2007 ($24) is a good entry-level chablis, with its orchard fruit and floral aromas, lively citrus flavor, and steely finish. —Jeffery Lindenmuth