I like to cook and freeze dishes. To start, pick a one pot meal - stew, chili, curries, or soup (easiest to get the hang of) - cook, cool, portion into individual containers, and freeze. Sauces like marinara, enchilada sauce, or BBQ sauce can be frozen the same way.
You can also freeze things like meatballs, homemade burritos, breakfast sandwiches, nuggets, taquitos, mini-pot pies, stuffed peppers, or mini-meatloves by cooking, cooling, freezing on a baking sheet (flash freeze) then transferring the frozen items into a freezer bag. The baking sheet keeps them from freezing together so you can take out as many or as few as you want to eat at that time.
Casseroles can be frozen for a few hours until semi solid, then cut into portions and you can put the portioned squares into a freezer bag to take out one serving at a time.
Batch/freezer cooking has been my savior.
details here. I've done it for about 8 years and I'll never look back. I cook VERY rarely during the week. Occasionally I cook something that isn't freezer friendly - like stuffed zucchini boats - at night after eating dinner so that we can just pop it in the oven the following day.
You can also prep crockpot meals at one time so that you can easily throw them into a crockpot in the morning with no prep
like this.
I pretty much make a breakfast frittata/crustless quiche and keep it in the fridge to heat up one piece every morning, then I grab one of my frozen portions of food and I pack it in my lunch bag. Sometimes I make a salad or grab something leftover instead, but at least 3 out of 5 workdays are usually something from my freezer.
We use components of freezer meals (like making pita pizzas with marinara that was pre-cooked), or having zoodles or pasta with meatballs (precooked), or cooking rice to go along with dal (precooked), or putting toppings on chili (precooked), etc so that dinners are easy. I admit that now that I'm no longer a single mother, we tend to eat more meat plus veg (and sometimes starch) meals.