I grew up eating Smash. We didn't have real vegetables in the East Midlands (we didn't have soil, just coal spoil) other than marrowfat peas which I have my suspicions about.
My staple meal as a child was Bird's Eye fish fingers, Smash mash, tinned mushy peas, and a packet of Knorr parsley sauce, carefully reconstituted and stirred and poured over the top (make a caldera in your mash is my advice for added mealtime fun). Oh noes, parsley sauce volcano!
OK, I lie, we had real potato in my mum's mince and potato pie. Mostly potato, the mince content was measured in ppm. If that, I think it was just potatoes and bisto.