Put a baking sheet on the bottom oven rack and preheat to 375 degrees F. Peel 4 pounds Yukon gold potatoes and cut into wedges. Toss with 1/2 cup olive oil, 6 chopped sage leaves, 2 sprigs sage, 2 teaspoons kosher salt and 1/2 teaspoon pepper. Spread on the hot baking sheet and roast 30 minutes. Stir, then add 8 smashed garlic cloves; continue roasting until golden, about 30 minutes. Increase the temperature to 400 degrees F and cook until crisp, 15 more minutes. Season with salt.