Mix 1 to 3 tablespoons wasabi powder with equal parts water to make a paste; cover. Make Classic Mash (No. 1); stir in the wasabi paste.
42. Sweet Potato
Roast 2 pounds sweet potatoes at 400 degrees until tender, 1 hour. Halve, then scoop out flesh. Puree with 4 tablespoons butter; add salt.
43. Sweet Potato Pie
Make Sweet Potato Mash (No. 42); stir in 1/4 cup maple syrup. Top with toasted pecans.
44. Cheesy Chard
Add 1/2 pound grated Gruyère to Classic Mash (No. 1); top with roasted tomatoes (No. 31) and cooked Swiss chard (No. 38).
Cook 1/2 cup diced prosciutto in olive oil until crisp, 6 minutes. Spoon over Sweet Potato Mash (No. 42).
46. Pumpkin Seed
Make Sweet Potato Mash (No. 42) with just 2 tablespoons butter. Saute 1/2 cup diced roasted poblanos, 1/4 cup green pumpkin seeds and 1 teaspoon cumin in 2 tablespoons butter; season with salt and spoon over the mash.
47. Sweet Potato-Apple
Make Sweet Potato Mash (No. 42); while the potatoes roast, simmer 2 chopped peeled apples in 1/4 cup apple cider with 1/2 teaspoon cinnamon until soft. Puree with the potatoes.
48. Sweet Spice
Make Sweet Potato Mash (No. 42); stir in 2 teaspoons pumpkin pie spice and the grated zest and juice of 1 orange.
49. Curried Sweet Potato
Make Sweet Potato Mash (No. 42); puree with 1 tablespoon curry powder and 3 tablespoons each plain Greek yogurt and mango chutney. Top with toasted coconut.
50. Root Vegetable
Make Sweet Potato Mash (No. 42); while the potatoes roast, boil 2 each peeled and diced parsnips and turnips until tender. Puree with the potatoes and butter; garnish with chives.
Photographs by Kana Okada