The chicken in this recipe steams on top of the vegetables as they cook on the stove.
In a large, deep skillet, combine tomatoes, fennel, and wine; season with salt and pepper. Arrange chicken breasts in a single layer on top of vegetables, allowing as much space between pieces as possible; season with salt and pepper.
Bring mixture to a boil; reduce heat to medium-low, cover skillet, and simmer gently until chicken is opaque throughout, 15 to 20 minutes.
Slice chicken breasts, and serve on top of vegetable mixture; garnish with reserved fennel fronds.
To slice fennel, remove stalks and fronds. Halve bulb lengthwise through the root. Cut out tough part of core from each half, and discard. Thinly slice crosswise (for most tender pieces).