Salt and pepper roast well. Place the butter in your pan and melt it over medium heat. Brown the roast on all sides in this butter. After browning add 1/2 cup water to the pan. Put sage and mint on the roast. Cover pan. Roast at medium heat ( 325 -350 ) for 3 hours if you like well done or 2 hours for rare. Every hour or so look to make sure there is at least 1/2 cup liquid in the pan. When done to your liking remove roast to a plate and keep warm.
Melt butter in a clean frypan over medium heat. Add flour to melted butter. Stir until well mixed with the butter. Remove from heat and add 1/2 cup cold water, The water must be cold, not hot, or hte flour and butter will become lumpy. Mix until a smooth paste is formed. Place the pan back on medium heat. Add sage and mint. Now add all the liquid from the roasting pan and mix it well. Stir all the time and let it boil slowly until thickend. Remove from heat and serve over roast.
The onion , garlic, seasoned salt and crushed red pepper are added to the roast before cooking. Red wine can be used instead of water while roasting (use water only in the gravy).