Cut peppers in half vertically, remove the seeds and membrane and transfer to a well-oiled baking dish. Cook farro according to the package instructions and transfer to a large bowl. To a skillet over medium heat add olive oil, onions and zucchini. Saute for a few minutes and then add garlic, diced tomatoes and spinach. Cook for about 5 minutes or until spinach is wilted. Season with oregano, salt and pepper and transfer to bowl with farro. Mix well. Spoon farro mixture into halved peppers, cover with foil and place into pre-heated oven for 20 minutes. While the peppers are in the oven, make the goat cheese sauce.
To a pan over medium heat add olive oil and chicken stock and simmer for 5-7 minutes. Add goat cheese, salt and pepper and mix until well combined and thick. Once peppers have been in the oven for 20 minutes, remove from oven, uncover and spoon goat cheese sauce over top. Return to oven and cook for an additional 10 minutes or until sauce is bubbling.