combine boiling water and Tomatoes in a bowl; cover and let stand 30 minutes or until soft. Drain and finely chop.
Heat 1 tsp oil in a large non-stick skillet over medium heat.
Add 1/3 cup Shallots, Sugar and Garlic; cook 4 minutes or until lightly browned, stirring frequently.
Spoon into a bowl, stir in 1 1/2 tsp vinegar.
Combine chopped Tomatoes, Shallot mixture, Cheese, Basil and 1/4 tsp Salt, stirring well.
Cut a horizontal slit through the thickest portion of each Chicken Breast half to form a pocket.
Stuff about 2 Tbsp cheese mixture into each pocket,
Sprinkle Chicken evenly with 1/2 tsp Salt and Black Pepper.
Heat 1 tsp oil in pan over medium-high heat.
Add Chicken; cook 6 minutes on each side or until done.
Remove Chicken from pan; cover and keep warm.
Add Broth, remaining Shallots, 2 Tbsp Vinegar, and Thyme; bring to a boil.
Combine Cornstarch and Water, stirring with a whisk.
Add Cornstartch mixture to pan; bring to a boil.
Cook 1 minute or until sauce is slightly thick, stirring constantly.
Serve sauce over Chicken.