It’s no longer a settled fact that cooking with gas (natural gas, propane) indoors is entirely safe. https://www.vox.com/energy-and-environment/2020/5/7/21247602/gas-stove-cooking-indoor-air-pollution-health-risks But it won’t kill you, and neither a properly run butane or propane stove that is rated for indoor use, for example. There are other methods that use liquid or gel fuels (e.g. denatured alcohol) that might be safer because there’s no risk of a gas leak (just noxious fumes). But if we’re talking about occasional use, I think that any stove rated for indoor use would be fine.