Actually, not currently. A combination of regulator-mandated nuclear plant stops, scheduled nuclear plant maintenance and fossil plant closures means that France currently relies on importing a lot currently.
Your statement is true generally, but France's situation currently contributes to high energy prices.
For cooking induction plates are much more efficient, transferring 90% of the energy as opposed to ~50% with gas stoves. Together with a gas plant efficiency of ~50%, they comes close in efficiency.
Gas stoves still come out on top price-wise, but part of that are asinine taxes, where gas is taxed less than electricity.
Thermodynamics says that it needs to dump heat somewhere, but maybe they can dump it into the atmosphere instead using hyperboloid cooling towers.
Those are huge though (at least "natural draft" ones are) and usually made of concrete, and making the concrete currently requires lots of carbon emissions.
France is self sufficient, but imports when prices are low in order to keep levels high in reservoirs, which further decreases prices over the year.