Perhaps your chicken breasts were slightly thicker than mine, AB, but good eye to notice that they required more time and adjusting! As for the toothpicks, I usually require them too, so don’t worry about that – totally normal! Just happy you enjoyed it 🙂

Beat an egg, brush it on the edges before you fold the meat. Once in the pan, use a spoon/instrument to press on the edges and ensure the egg cooks quickly. That will create seal the prevents the cheese from spilling out.

Hello Bart. Some cheese spilling out is inevitable, it’s even spilling out a bit in my photos. You can never truly “seal” the chicken, but by rolling it and folding the edges under, that’s the “seal” we’re looking for.

Under my “cooking tips” I wrote the following:
Seal the edges: When assembling and closing the cordons bleus, make sure you seal the edges well to prevent the cheese from oozing out. Leave a rim around the filling, fold the sides of the bottom part of the chicken breast over the filling before closing with the top part. Optional: You can also secure the ends with toothpicks or kitchen twine, and remove them after cooking.

Hope this helps!