In a medium pan, cook potatoes in enough salted water to cover them until tender (about 15 minutes). Drain the potatoes and return them to pan.
Melt margarine and olive oil in heavy medium skillet over medium heat. Add sliced shallots and cook until tender and brown, stirring often, about 20 minutes. Transfer shallots to small bowl. Add Manischewitz® beef broth and garlic to the skillet. Bring to a simmer, scraping up any of the caramelized bits stuck to bottom of pan. Mash the potatoes, adding the hot beef broth, until they are the desired consistency. Stir in the caramelized shallots, basil, mint, Kosher salt and pepper.
Chef's Tip: Multi-task—boil the potatoes and start the shallots at the same time. The potatoes will be drained and ready for the shallots for the perfectly timed mashed potato!