Dry the bread that you will be using overnight (see note for quick alternative). If pieces are thick, consider cutting into thinner slices for better drying.
Crumble dried bread into manageable pieces (about quarter sized) then place about a third of the bread pieces into a blender or food processor. Cover and pulse until coarse crumbs form, about 2 minutes. Repeat with another third of the bread, then with the final third plus the herbs, salt and pepper.
Transfer to an airtight container and store at room temperature.
Notes
For a low (no!) tech method for "grinding" the bread into crumbs, place between wax paper or parchment and roll with a rolling pin.If your bread isn't fully dry, you can toast it before or after grinding.
I am not a health professional and nutrition data is calculated programatically. Accuracy may vary with product selection, calculator accuracy, etc. Consult a professional for the best information.