Cut chicken breasts into about 1-inch chunks or flat pieces. Heat olive oil in a large non-stick skillet or wok if available. Saute chicken pieces for about 5 minutes or until slightly browned. Then add the shrimp, cooking another few minutes until cooked through. Add broccoli and bell pepper, saute a few minutes enough to retain crispness.
In a saucepan, mix together chicken broth, cider vinegar, soy sauce, sesame oil, and minced garlic. Bring to a boil over high heat, stirring constantly, a few minutes and then reduce to low. Add cornstarch/water mixture, simmer and stir vigorously to avoid clumping.
Pour sauce into the skillet and mix ingredients together until thoroughly coated. Cook for another few minutes until ready to plate.
Garnish with sesame seeds and serve with rice .
*Just a reminder to continually taste-test your sauces (especially when making them separately) throughout the cooking process. Even the most exact measurements of ingredients usually do not produce the same results. What's spicy, salty, bland, sweet, and sour to me will most likely be different than your taste profile. This helpful tidbit works well with all recipes and it's something I remind myself while cooking.