For spice rub:
2 teaspoons salt
1 teaspoon black pepper
1 teaspoon granulated garlic
4 pound boneless leg of lamb
For Port wine sauce:
1 1/2 cups red wine
3/4 cup Port wine
4 tablespoons butter, room temperature
For fried potatoes:
12 medium gold potatoes, cut into 1/4" slices
1/2 cup chicken broth
1 teaspoon dried cilantro
Preheat oven to 400 degrees F. Mix together dry rub spices in a small dish and rub all over the outside of the lamb. Heat 1/4 cup vegetable oil in a large, heavy skillet and sear lamb on all sides. Transfer to a roasting pan that has a drizzle of olive oil in the bottom. Roast 1 hour 20 minutes for medium (about 140 on a meat themometer).
Meanwhile, pour red wine and Port into a small saucepan, bring to a boil and let it reduce to about 1/3 cup (about 20 minutes). Remove from heat, season with a dash of salt and a pinch of pepper and stir in butter.
Meanwhile, make potatoes. In same skillet that you seared the lamb, fry potatoes until golden, turning occasionally. Season with 1 teaspoon salt and 1/2 teaspoon pepper. Pour in chicken broth and cilantro, lower heat to medium low and cook until tender, about 10 minutes.
Remove lamb from oven, tent with foil and let it rest for 10 - 12 minutes before slicing. To serve: Line a large platter with the potatoes, arrange lamb slices on top and drizzle with Port wine sauce. Serves 8.