Instructions

Cut each fennel bulb lengthwise through core into 8 wedges (do not remove core); set aside. Cut away peel and pith from oranges. Holding fruit over bowl, use paring knife to slice between membranes to release segments. Squeeze remaining juice from membranes to yield 2 tablespoons; set aside. Cut segments in half and place in second bowl.
Bring bratwursts and ¼ cup water to simmer in 12-inch skillet over medium heat. Cover and cook until bratwursts register about 135 degrees, 5 to 7 minutes. (If skillet contents begin to sizzle, add ¼ cup water.)
Uncover and, using paring knife, pierce each bratwurst in 8 to 10 spots to release fat and juices. Continue to cook, uncovered, moving bratwursts as necessary, until dark fond forms on bottom of skillet, 2 to 4 minutes longer. Transfer bratwursts to cutting board.
Add wine, 1 tablespoon oil, salt, pepper, and remaining 1¾ cups water to now-empty skillet. Stir, scraping up any browned bits. Add fennel wedges, arranging them cut side down in single layer. Add olives and bring to boil over medium-high heat. Adjust heat to maintain simmer; cover; and cook until fennel is tender, 10 to 12 minutes. Flip wedges and continue to cook, uncovered, until liquid is reduced by half, 5 to 7 minutes longer.
While fennel cooks, add 2 teaspoons fennel fronds, vinegar, cornstarch, honey, and remaining 5 teaspoons oil to reserved orange juice and whisk to combine.
Return bratwursts to pan, nestling links between fennel. Cover and continue to cook until bratwursts register 160 degrees, 7 to 12 minutes. Transfer bratwursts to cutting board and slice each link into thirds.
Whisk orange juice mixture to recombine, then add to skillet. Cook, stirring constantly, until sauce is thickened and glossy, about 1 minute. Off heat, season with salt and pepper to taste. Divide fennel and sauce among shallow bowls. Top with bratwursts and orange segments and garnish with remaining 4 teaspoons fronds. Serve.