I have very little energy and find it painful to stand for more than a few minutes, so do very little cooking these days.
Easy options: sprinkle lemon juice or spices on chicken pieces or fish fillets, wrap in foil and bake (about 15mins for fish and 25-35 for chickens depending on the size*). Reheat the next day - fish in the microwave and chicken sliced and stir fried for less than a minute. Eat with microwaved cauliflower rice and spinach/green beans/broccoli - frozen packs of cauliflower rice and individual prepared packs of green veg.
When I have help I get grated fresh cauliflower, roast it in the oven with a little oil for about 12 mins then cool and bag, I microwave these from frozen.
I buy ready made salads to eat with cheese/prawns/meat.
And I 'fry' onion using bags of ready chopped onions, put into a oiled pan and cooked for about 3 minutes with the lid on then take off the lid, turn up the heat and fry them until browned. Add to mince and fry for a minute, then into the slow cooker with a tin of tomatoes and some dried or fresh garlic. I split the mix and make half into spaghetti sauce to eat with courgetti noodles and salad, and the rest has a chilli mix added to eat with cauliflower rice and green veg - it makes two meals of each and keeps in the fridge for 3/4 days.
*I have a combination oven/grill/microwave so there is no heating time needed as the oven heats up in a minute or two.