I tell people that my go-to meal for dining alone is a can of tuna and a multivitamin, but I can exclusively reveal to you, dear PASers, that actually I usually skip the multivitamin.
Let's see, for throw together as opposed to a made ahead freezer meal...
Steak au steak, as Emma put it, preferably rump or something with flavour (not eye fillet). Cooked on a smoking hot grill/pan only just so long that a good vet could get it back on its feet. While that's resting, throw a large mushroom or two on the grill and follow with thinly sliced zucchini. Deglaze with wine and pour over the steak. Maybe couscous or good bread for a starch/soaker for the juices. (Pandoro used to do a beef on five grain sandwich that was the original inspiration for this).
Thinly sliced meat (perhaps a quick marinade) and veges done in the wok, add hoisen, soy, chilli, stock etc as required for taste/amounts required to make sauce or soup as required - instant brown rice for starch/bulk out the next day lunch.
In a pan fry off a clove or three of thinly sliced garlic in olive oil, option to add bacon/ham at this point, add some cream and bring to the boil until it just starts to caramelise. Season with pepper and mix with just cooked fresh pasta noodles