For indoor cooking, ethanol is one of the safest options because they shouldn't produce carbon monoxide or other harmful pollutants. [1] [2] However, it's important to monitor the burning to make sure that incomplete combustion isn't happening, as this can generate more harmful pollutants. [1] [2] [3]
There are some larger alcohol stoves available out there: [1] [2] [3] [4]
Cooks often use portable cooktops that run on butane, indoors, and have basically no problem. [1] So that's a good option too. [2]