When you are vegetarian, and especially vegan, you do seem to spend a fair amount of time on food preparation, compared to the days when meat-and-a-side graced our tables. Part of me enjoys the preparation- it's part of the practice of eating mindfully; and moreover I enjoy cooking- the anticipation of good food lovingly prepared is a pleasure in itself. I may only be planning to have a giant delicious salad for lunch, but preparing something wonderful for dinner is an observance that dulls the edge of any sense of deprivation I might momentarily feel.
There are lots of ways to expedite vegan food preparation... Think in terms of things like a big container of pre-cooked quinoa or even rice in the fridge to be used in salads, soups or what have you as the wish arises. Likewise an idea I got from a wonderful (non-vegan but very pro-wonderfulness) book called 'An Everlasting Meal' by Tamar Adler is to have a big weekly roast-up. When I return from the market with a boot full of fresh stuff, it may include goodies such as bunches of raw beetroot (pendant from their bunches of exquisitely red-veined dark green leaves); ears of sweet corn, pumpkins, kale (finally found it in Australia!), carrots, beans, broccoli, cauliflower, potato and sweet potato- you get the picture. If it's not specifically a salad vegetable, I usually include it in the Big Roast Up. Like Tamar, I roast and then happily eat all kinds of odd greens- beetroot greens are an obvious fave! But also the green part of a cauliflower, and the stems of broccoli are delicious roasted.
With the oven on and hot, I stow trays of the above veggies- things like beetroot in a bit of water covered with foil, pumpkin in large pieces with skin on, half a head of cauli, etc. I keep the oven full and rotate the trays of veggies out as they become cooked, Then the cooked goodies go into the fridge, to be used in recipes, salads, or just eaten during the coming days. I figure that if I cook it fresh, it stands a better chance of being eaten than after several days shrivelling in the fridge. I love having cold cooked pumpkin at the ready, for pizza, salad, rissotto or to have on toast.
Along with always soaking beans, because you will want them tomorrow or the next day, the Roast Up is my favourite efficient-vegan habit.