Recommendations for breakfast and dinner in Paris
Protein at breakfast is not all that common in Paris, unless you're counting yogurt. A typical Paris breakfast will be bread and/or croissants, butter, jam, juice, and coffee.
There are a couple of places that sling up an American breakfast (and a couple more that do a British fry-up) -- but they're the exception.
Might be better to grab a "regular" Paris breakfast, then pick up some cheese or a hardboiled egg from a small shop (Monop, Huit a 8, etc., )