In a large pot heat the oil and bacon over medium heat until bacon is rendered and crisp. 5-7min

Add onions and celery 3 to 5 minutes in the garlic chopped (or to desired size) and red pepper to cook for 1min.

Add the collard greens stir well. Add chicken broth and vinegar.

Add sugar, salt and pepper.

Cover partially the pot. Lower heat to low cook for 30-40 min.