Heat oil in 2-quart saucepan over medium heat and cook onion, thyme, rosemary, salt, pepper, and paprika, stirring occasionally, 4 minutes or until onions are translucent.
Stir in Riesling and bring to a boil over high heat. Reduce heat to medium-low and continue cooking, stirring occasionally, 15 minutes or until reduced by half.
Add peaches and brown sugar. Simmer over medium heat, stirring occasionally, about 20 minutes or until sauce is thickened. Strain liquid through mesh sieve into a medium bowl. Gently stir and push some solids through sieve. Whisk in mustard; cool slightly.
Preheat oven to 325°F.
In a roasting pan fitted with a rack, add 3 cups of water.
Place ham on rack and brush generously with peach glaze. Tent with foil.
Cook 30 minutes. Remove foil and brush with glaze. Continue to brush with glaze every 30 minutes for an additional 1-1/2 to 2 hours or until ham reaches internal temperature of 160°F.
Let ham rest 5 to 10 minutes before serving. Serve with any remaining glaze.
Twist on a classic: Substitute ground cinnamon for the smoked paprika and substitute a robust red wine such as cabernet or merlot for the Riesling and canned diced pears or apples for the peaches. For a festive look, garnish ham with fresh thinly sliced pears or apples and fresh rosemary and thyme sprigs.