Don't call it cheating; call it a shortcut.
Very few of us these days have the time or energy to make phyllo dough from scratch or even to simply chop vegetables. And if you're trying to host a nice dinner for friends or cook a good meal for your loved ones, there's absolutely nothing wrong with using the shortcuts available to you if you're pinched for time.
I'm not talking about going full-on Sandra Lee, of course, but rather knowing how to pick out the right items in the store that will cut your gourmet cooking time in half without sacrificing flavor or presentation. Sure, you'll pay more for the convenience -- and I wouldn't recommend shopping like this on a daily basis -- but it's good to know the shortcuts are there when you need them.
Most grocery stores these days have pre-chopped vegetables for nearly every occasion, ready to go in the produce department. You can get portobello mushroom caps pre-stuffed for the grill, bell peppers and onions pre-sliced for fajitas, even containers of diced onions, celery and carrots for a ready-made mirepoix. Sure, the cuts are rougher than you'd probably make yourself, but the time saved is worth it. You can find similar mixes in the frozen section, where some vegetables -- like green peas -- are typically better than the fresh ones in the produce department.
When you don't have time to make a pasta sauce, turn to reliable standbys like the vodka sauce from Rao's or Giada De Laurentiis's tomato basil pasta sauce (they're both consistently rated well by publications like Consumer Reports as well as by my stomach). Other sauces can be more difficult, though. Powdered Hollandaise for the Eggs Benedict you're trying to make to impress at brunch? It could be a disaster. H-E-B carries a line of pre-made sauces such as Hollandaise that are actually fairly close to the real thing, however. Just look for them in the meat department. Spec's on Smith also has a good selection of acceptable powdered sauces (other than the standard Knorr's that we all know and...tolerate?) near the deli.
A salad is already inherently easy to make, right? There's not even any cooking involved. But the prep work can be time-consuming. Buy a bagged salad mix that comes with fruit and/or nuts, then top with goat cheese crumbles from the cheese department and a quick vinaigrette you can make yourself in less than a minute.
No one needs to know you didn't make that crabcake. In fact, these are one of the things I'd advocate buying pre-made at Whole Foods or Central Market because theirs are so damn good you'll want to pass them off as your own. Top with a dollop of crème fraîche and some fresh herbs or microgreens (if you want to get real fancy). Most of the pre-stuffed and/or marinated fish is good, too, and perfect for a quick broil in the oven or turn across the grill.
H-E-B has these fantastic pre-rolled beef pinwheels that can pass as beef braciole in a pinch, and equally good pre-seasoned fajita meat (for those bell peppers and onions you picked up earlier). Most stores also have pre-breaded chicken that can pass as a decent chicken parm dish, especially with some good sauce on top and a pretty salad on the side.
Frozen sweet potato fries are probably the best thing to come out of the frozen foods section since ice cream and peas. They crisp up incredibly well in the oven, only take a few short minutes to cook and everyone loves them. Ditto frozen cauliflower: Just roast it with olive oil and salt, finishing with a little cracked black pepper at the end. Pre-cooked rice is getting increasingly good, although pre-cooked/instant mashed potatoes still aren't. Leave those behind.
No matter how tempting it may be to buy those pre-assembled cheese plates you see at places like Murray's inside of Kroger, don't. They are rarely -- if ever -- good, although I still fail to understand how that gets messed up so easily. Instead, go to Murray's or the cheese department at Whole Foods and look for the "small" pieces of cheese (the nub-ends or trimmings left when larger wheels were being sliced up). They cost less and look prettier on a cheese plate and they come to room temp much faster.
Four words: frozen puff pastry dough. You can wrap anything inside of it, bake it and call it a triumph. Ditto those tiny pastry cups: Fill them with pre-made lemon curd, top with whipped cream, a few berries and perhaps a little lemon zest and you'll look like a champ -- with no baking involved.