Cook ham in medium saucepan on medium-high heat until lightly browned on both sides. Set aside; keep warm. Reduce heat to medium. Melt butter in pan. Add flour; cook and stir with whisk until it is the color of peanut butter, about 5 minutes. Slowly add bone broth, a little at a time, while whisking constantly. Add coffee, sugar and salt; cook until gravy begins to bubble and thickens slightly, whisking occasionally. (Gravy will continue to thicken upon standing.) Serve over ham, biscuits or grits, if desired.