Ingredients

• 1/2 cup mayonnaise
• 1 tablespoon extra-virgin Olive oil
• 2 garlic cloves, pressed
• 2 teaspoons tomato paste
• 1/8 teaspoon smoked paprika
• Pinch of cayenne pepper
• 1 1/2 pounds unpeeled russet potatoes, scrubbed, cut into 1-inch cubes
• 1/4 cup whole milk
• 2 tablespoons (1/4 stick) unsalted butter
• 1 teaspoon coarse kosher salt, divided
• 3 1/2 tablespoons extra-virgin olive oil, divided
• 1 cup chopped onion
• 1 large garlic clove, finely chopped
• 1/2 pound kale, center rib and stem cut from each leaf, leaves coarsely chopped
• 1 tablespoon chopped fresh thyme
• 1/8 teaspoon ground nutmeg

Instructions

1. Whisk all ingredients in medium bowl. Season rouille to taste with salt and freshly ground black pepper. DO AHEAD: Can be made 1 day ahead. Cover and chill.
2. Cook potatoes in large saucepan of boiling salted water until tender, about 25 minutes. Drain; return potatoes to same saucepan. Add milk and butter. Mash potatoes (with peel) until smooth. Season with 1/2 teaspoon coarse salt and 1/2 teaspoon pepper. Transfer 3 cups mashed potatoes to large bowl and cool (reserve remaining potatoes for another use).
3. Heat 1 1/2 tablespoons oil in large deep skillet over medium heat. Add onion and garlic. Sauté until onion softens, about 5 minutes. Increase heat to medium-high. Add kale and thyme. Toss until kale wilts, about 5 minutes. Add kale mixture, 1/2 teaspoon coarse salt, 1/2 teaspoon pepper, and nutmeg to potatoes; blend. Cool potato mixture 30 minutes.
4. Shape potato mixture by 1/4 cupfuls into 1/2-inch-thick patties. Arrange on rimmed baking sheet. DO AHEAD: Can be made up to 2 hours ahead. Let stand at room temperature.
5. Heat 2 tablespoons oil in large nonstick skillet over medium-high heat. Add cakes and cook, without moving, until cakes are brown and crispy on bottom, 3 to 4 minutes. Carefully turn cakes over. Cook until brown on bottom, 2 to 3 minutes longer. Transfer to plates. Top each cake with dollop of rouille.