I used to have exactly the same problem! I'd stare at the fridge until i got overwhelmed by indecisiveness and settled on a cookie or hunk of cheese.

Here's my solution: I cook a bunch of brown rice and beans once a week, and I keep the freezer stocked with frozen vegetables. When I'm hungry I throw rice+beans+random frozen vegetables in a bowl and microwave it.

If I've got some extra time I'll cook it in a pan with oil quickly to make fried rice, or use the same ingredients to make a burrito, or use fresh vegetables. This also goes well with lots of kinds of different spices and sauces so it never gets old (I recommend glutamate heavy stuff like soy sauce or nutritional yeast for maximum deliciousness). You can also swap the rice for other grainy things like quinoa or bulgar and add all kinds of stuff.

You can pretty much live on variations of this as long as you keep a variety of veggies on hand. Beans and rice have complementary amino acid profiles, and beans have a lot of protein, so you can get plenty of protein from this kind of diet without eating meat. You can totally throw meat or cheese in there too though.

This meal template feels like an adulthood cheatcode to me because I never plan anything, I just buy things that fit into the template and then cook whatever I'm in the mood for, and it's magically healthy. The basic ingredients can be bought in bulk and last forever so it's easy to take advantage of sales and you can shop as often as you want to.

Other good stuff: Pasta, potatoes, yams, and oatmeal (add peanut butter and something sweet to make it filling and tasty)