I never knew you could freeze beetroot until this morning!
It needs to be cooked, it goes mushy if frozen raw. Leave the tops and tails on, clean well and boil till tender. Peel (just slides off with fingers) trim and chop into pieces desired. Put on tray and into freezer to free flow, then bag. Easy peasy….not sure how good the texture will be when baked but apparently fine. I .did 2 trays of these today
Leeks – I do every year like this with no loss of flavour or texture. Just wash, slice, freeze. I have done 8 bags but didn’t photograph as they are frozen and bags are white.