For the salad: In a medium bowl, whisk together the garlic, shallot, salt, lemon zest and juice, and the orange zest and juice. Fold in the shaved fennel, fennel fronds and dill. Toss to coat. Add the orange segments, a few grindings of black pepper, coriander, olive oil and watercress. Toss gently.
For the chicken: Put a large skillet over medium-high heat.
Add the olive oil to the hot pan. Season both sides of the chicken with salt and pepper. Arrange 4 pieces of chicken in the pan and cook until golden brown, about 3 to 5 minutes. Flip and cook until light golden brown, about 3 to 5 minutes.
Put the chicken on plates, top with the salad, spoon additional dressing over each portion and serve.