Place beef shanks in a large frying pan, adding water, onion, carrot, bay leaf, whole black peppers and boullion cubes.
Bring to boil, cover, and simmer slowly approximately approximately 45 until tender. Cool slightly in liquid.
Remove shanks, cutting off excess fat, discarding bones if desired. Drain stock and place in bowl in refrigerator to bring fat to the top while doing second step.
Melt butter in same frying pan and turn off heat.
Stir in mustard, horseradish, basil. and lightly add salt and pepper.
Dip shanks into coating mixture, then put aside.
Cut squash that had been cut in half lengthwise. Dip squash in same mixtures and put aside.
Place beef and vegetables cut side down on grill racks sprayed with cooking oil. Place 6" inches over medium-hot coals or cook indirectly on left side of gas grill with right jets turned on to medium-high.
Watch and turn as needed until meat and squash are brown and tender (do not burn squash) about 10 to 15 minutes.
Lightly butter squash and place on serving plate or bowl.
Place meat on another platter. If desired, remove fat from leftover stock from Step 1, season if needed, and reheat. Drizzle stock over meat.
Serve with mashed potatoes or seasoned potato wedges done on grill, along with a nice fruit salad.