The VEGETABLE.  They are both hard and easy.  It depends, as always, on how you torture them originally.  Indian Spiced Carrots have limited purviews but a simple steamed head of broccoli can go many places. The best approach to reuse of cooked foods is to aim for the simpler methods first, light on the seasoning, with added complexity with each iteration.

Starting with leftovers is often nice when you are cooking for one. It reduces cooking time and dishes, and can help add a little variety when you have a family package of something to finish up. Having the cooked vegetable right there– front and center– in your fridge can make it easier to prep them. So, it could help you eat more vegetables. Keep them at eye level, and make up a list of what you can do with yours to post on the front of the fridge. Resisting the urge to just have frozen french fries with your sandwich is easier when you can throw together a roasted carrot dip in less time.

Pre-cooking your vegetables intially also offers the advantage of adding life to you vegetables. Steamed broccoli generally stays pretty hardy for 5-6 days if you rinse it with cold water immediately after cooking. By that point, it might have faded a bit if it were still sitting in your vegetable crisper. This is particularly noticable with more delicate vegetables like summer squash.

I believe in teaching by examples, so here you go…

Stage one: the basics
Steamed broccoli
Sauteed spinach with garlic
Roasted carrots

Stage two: a little dressy
Chopped broccoli a la vinaigrette (aka broccoli in salad dressing), with a little thinly sliced shallot and some parmesan or goat cheese
Cream of broccoli soup

Spinach, topped with an poached egg, on toast
Spinach artichoke salad: mix chopped marinated artichoked with spinach and a little lemon juice and olive oil

Pasta (or rice or quinoa) salad: toss carrot with a vinaigrette, minced scallions, feta, and some fresh mint
Roasted carrot dip: puree carrots with coconut milk and top with chopped almonds roasted with curry powder OR puree carrots with cook white beans and fresh dill

Stage three: full on white-tie

Broccoli sandwich: toss the salad into a pice or rice paper wrappers along with some chickpeas or leftover meat. Add mustard, lettuce, and tomato to taste.

Broccoli casserole: pour remaining cream of broccoli soup over a mixture of rice and leftover steamed broccoli. Top with breadcrumbs and cheese and bake until heated through.

Spinach artichoke patties: mix the spread with an egg and shape into patties that you bake or cook on a griddle
Spinach pancake: mix with cooked potato and cheese. Press into a baking pan and bake until crispy.

Roasted carrot soup: thin further and enjoy hot!
Mash remaining roasted carrots and substitute for pumpkin in muffins, pancakes, or waffles.

Last ditch effort:
Add to smoothies (carefully, in small amounts)
Make vegetable stock
Chop finely and mix with rice or into bread dough. Nobody will notice…

Mission: eat more vegetables! Most creative idea in the comment section wins a package of homemade muffins.

Vegetable Hash
Thrifty Readers Share Kitchen Tips
The Use-it-up Cookbook