I'm a big fan of spaghetti. You can sneak odds and ends of vegetables into the sauce, and use whole-wheat pasta, to improve the nutrition.
We also eat a lot of pasta with assorted vegetables, olive oil, nutritional yeast flakes, and sunflower seeds.
Full recipe here.
Scrambled eggs are quick and easy! Make a burrito with cheese and salsa, or just eat eggs with whole-wheat toast and fruit.
Canned beans are great all kinds of ways! You can get baked beans and just heat and eat. Plain beans (black, kidney, pinto, etc.) drained and cooked with onions and chili powder and maybe a little tomato, are good in burritos or with rice. Lately I've been making a bean sandwich that tastes kind of like a cheeseburger:
Brown diced onion in oil.
Add beans, ketchup, mustard, and black pepper. Stir until heated.
Serve on bread or bun with cheese, lettuce, and/or tomato, as desired.
Another great burrito filling is sweet potato. Mash up canned ones (syrup drained off) or baked ones (peeled) and mix with browned diced onions and chili powder. Add grated cheese.
I like to squeeze the water out of a pound of tofu, cut it into bite-sized pieces, and submerge it in a tasty sauce in a container that seals tightly. Then it's ready to cook quickly, whatever amount you want, and eat with rice or salad or whatever you have handy. It's good for 4-5 days, more if you use vinegar in your sauce.
Whenever we cook rice, we make a big batch and put away the extra to re-heat for future meals, as a side dish or to make into fried rice.
I buy kale, use some of it fresh, and freeze the rest. Here are
freezing instructions and ways to use kale.
We eat oatmeal for breakfast and snacks quite often. Quick oats are almost as nutritious as slow-cooking ones and as convenient as "instant": you can cook them right in your bowl by pouring boiling water on them and stirring. Add all kinds of tasty, healthy stuff--I like almond or cashew butter, raisins or cut-up dried apricots, ground flax seeds, sorghum syrup, cinnamon, and ginger.
Honey Baked Lentils bake for over an hour, but they're so quick to put together that I consider them a convenience food.