So far this week we have had Cholent, beef bourguignon, Chicken Gumbo and Chicken Hotpot all done in a slow cooker. It takes about 10-20 mins to prepare either last thing at night or first thing in the morning. For more complicated dishes like Lasagne or Mousaka we prepare them at the weekend put them in the fridge and stick them oven on a timer for when we come home from work.
Most cooking doesn't take that long with planned preparation, you wouldn't sit in a restaurant for and hour or so waiting for your minute stake. The chef from experience knows how long it will take him to prepare and dish up.
Invest in good cookbooks that tell you preparation time.
We plan our weekly meals at the weekend and do an on-line shop accordingly. It does take the spontaneity out of it a bit and from time to time you come home and think to yourself "I really don't fancy what's in the slow cooker/oven" but, then my wife and children do and so I just join in.
A note on veggies, most veggies (except for spuds and other root vegetables- but they go in the slow cooker) should not be cooked longer than 10 mins or so. So if you've chopped up a cabbage the nigh before just drop it in a pot of boiling water and there you have it. You could get a steamer and pre-fill it and put it on a timer.
Just to give a bit of context we are a working family of four. Myself and my Wife both work 9 to 6ish sometimes later. Our children are 5&7 and both at school. Every evening at 7ish we sit down for a family meal. We are a nuclear family with only after school child-minding from 5:30 until we get home.