A microwave oven uses much less electricity than either a stove top or oven, about a third as much. On the other hand, some foods need baking, broiling, or searing to bring out their best flavors. When I use the full size oven, I often fill it up with a pan of chicken and three pans of vegetables to roast. When I’m baking something small, like baked potatoes, I use the toaster oven. I use the micro-wave for reheating.
A pressure cooker will cook food in about 1/3 the time that conventional cooking takes. The best foods for this are foods that can be cooked with liquids, because the cooker needs steam to work. This is great for rice and for beans, and it also works for meats and vegetables.
Solar ovens use no energy at all, but there are disturbing reports of vision damage from the reflectors.