Combine first 6 ingredients in a small bowl; set aside.
Unroll roast; trim fat. Rub ginger mixture into folds and over surface of roast. Place roast in a large zip-top plastic bag; seal and marinate in refrigerator 12 to 24 hours, turning bag occasionally. Remove roast from bag; set aside.
Preheat oven to 325°.
Heat the oil in a Dutch oven over medium-high heat; add roast, browning on all sides. Add onion, wine, garlic, and broth, and bring to a simmer. Insert meat thermometer into the thickest portion of roast. Cover and bake at 325° for 50 minutes or until thermometer reaches 145° (medium-rare), basting occasionally. Remove from pan; set aside, and keep warm.
Strain cooking liquid through a sieve into a bowl, and discard solids. Return cooking liquid to pan. Bring to a boil, and cook 5 minutes or until reduced to 2 cups. Combine flour and water in a small bowl; stir well with a whisk. Add flour mixture to cooking liquid in pan. Bring to a boil; cook 1 minute or until slightly thick, stirring constantly with a whisk. Stir in Spiced Pear Butter; serve sauce with lamb.
This is beyond delicious! I made the pear butter, and it is yummy, too. Dinner guests raved. Husband couldn't stop eating. Served with whole wheat couscous and green beans. Great winter or fall dish. Will make it again for sure.
Very good, nice change. Made to recipe except used prepared apple butter as the base for CL's spiced pear butter. With that change this became a pretty easy dinner. Served with simple roasted yukon golds/carrots/onions and steamed haricots verts.