You might consider a halogen oven - they sell them on the TV sales channel - one with a flip up lid on a hinge is the best design. They are not expensive and they have a temperature and a timer - it is so easy to do full dinners or small snacks - more economical that a big oven and you can put veges underneath and meat on a grid and have your meal all cook together. Once you get the basic principle - start the meat cooking, turn it over at the same time as adding the veges, turn the meat over again and stir the veges at the same time, finish cooking, you can do all sorts of meals with very little effort.
Fried foods, done in a pan or an electric grill are quick and can be both low carb and filling.
Filling up the freezer with suitable foods, then bringing out some to defrost for when you come home is a great help.