Meanwhile, cook the vegetables in boiling water for 3-5 minutes. Set aside. Heat the oil in a large frying pan over low-medium heat. Add the garlic and saute until softened. Increase the heat to medium. Add the sausage meat, stirring to break up, and cook for 5 minutes, until browned. Add the broccoli and celery, decrease the heat to low and cook for 10 minutes, until flavors have developed. Season with salt and pepper.