Melt 1 tablespoon butter in a large nonstick skillet over medium heat. Add fennel bulb, leek, and fennel seeds; cook for 2 minutes, stirring frequently. Stir in salt. Cover and cook 12 minutes or until fennel is tender, stirring occasionally. Set aside.
Combine broth and wine; bring to a simmer in a large saucepan (do not boil). Keep warm over low heat (mixture will look curdled).
Melt 1 tablespoon butter in a medium sauté pan over medium heat. Add orzo to pan; cook for 2 minutes, stirring constantly. Add broth mixture, 1/2 cup at a time, stirring mixture frequently until each portion of broth mixture is absorbed before adding the next (about 17 minutes total). Stir in leek mixture; cook 2 minutes. Remove from heat; stir in cheese, fennel fronds, and pepper.