Cooking for oneself is a great way to save resources and therefore spend less money.

Some folks set up on a tailgate or on little table at the rear of the vehicle under the open hatch, or with the rear door open and blocking view/wind. At parks stoves can be set in a bbq grill or on a concrete picnic table.

For folks looking to save more on food expenses, there are cheap but tasty approaches.

stoves

ovens

Cookware

Plates and eating utensils

Cooking with excess solar/alternator power, including crock pots.

There are a couple main issues: water conservation and workspace.

• focus on single-pot meals so only one pot is dirty. Eat out of the pot.
• “deglaze” (add small amounts of water, broth, wine, etc) the hot pan to get as much flavor into your dish as possible¹⁾
• either clean ASAP (oatmeal and other stuff that dries on) or soak

Scrambled eggs are notoriously difficult to get off pans. Some techniques:

• don't eat scrambled eggs consider poaching or hardboiling eggs to minimze cleanup
• heat the pan, then add a bit of oil and allow to heat. Spread evenly, cook.
• after cooking, scrape off what you can with a flat wooden implement, then put a small amount of water (doesn't have to be potable) back into the pan and bring to a boil. Simmer or allow to soak. Scrape again.

Since carrying measuring cups and spoons can be unwieldy in a vehicle, 'dwellers may want to measure their ingredients by weight.

* YT search on learning to cook