면 되다

just do X and it's fine

Names one condition and says meeting it is enough — pour the gravy and you're done, just prepare onions, just keep doing what you've been doing. It reassures rather than orders, which is why cooking and how-to lines lean on it so heavily. Compare 어야 되다, which stresses that something is required; 면 되다 stresses that nothing more is required. As a question it checks whether one step will suffice ("do I just type it all in lowercase?").

Register: everyday spoken; instructions and reassurance