Chicken with Tomato-Balsamic Pan Sauce

Ingredients

• ounce boneless, skinless chicken breasts
• teaspoon salt, divided
• teaspoon ground pepper, divided
• white whole-wheat flour
• tablespoons extra-virgin olive oil, divided
• halved cherry tomatoes
• tablespoons sliced shallot
• balsamic vinegar
• low-sodium chicken broth
• tablespoon minced garlic
• tablespoon fennel seeds, toasted and lightly crushed
• tablespoon butter