Take care cutting the squash. It will be HOT.
Cook spaghetti squash in the microwave oven. Carefully pierce the squash 6 or 7 times. Cook on high for 10-12 minutes, turning half way. Cook until a fork inserts easily through the skin and into the flesh of the squash. Repeat with 2-minute increments until you can insert the fork. Let stand at least 5 minutes before cutting in half. The squash will be HOT so hold it in a towel or wear gloves when cutting it in half. Scoop out the seeds and guts with a large spoon. Discard. Use a fork to really separate the strands and scrape the flesh out of the shell. While the squash is cooking, season chicken breasts with ground black pepper and garlic salt. Heat olive oil in a medium skillet and brown the onion and seasoned chicken breasts. Pour tomatoes, tomato sauce and balsamic vinegar over chicken, and season with basil, oregano, rosemary and thyme. Simmer until chicken is no longer pink and the juices run clear, about 15 minutes. When the spaghetti squash is cooked, cook the green beans according to package instructions. Plate all and enjoy.