Add the onions and fry them, adding more oil if necessary, until lightly browned, about 10 minutes. Add the garlic and cook for another minute. Add the vegetables and cook for another 5 minutes. Return the beef and bacon to the pot along with the remaining ingredients and stir to combine. Add stock a little at a time and deglaze. Bring it to a boil. Reduce the heat to low, cover and simmer as long as possible. Add salt and pepper to taste.