Do we hold that one shouldn’t take a piece off the bread with one hand and eat with the other hand?
The rule of not holding the food in one hand and tearing off a piece with the other hand applies only to food which is on a plate. Food which is normally held by hand such as bread may be eaten that way.
דברי חמודות חולין ח, צד. הגהות מהר״א אזולאי ללבוש קע, ה. א״ר שם יא. שמן המאור שם ט.