How to Make It
Preheat the oven to 350°. Spread the pecans and cashews on a rimmed baking sheet and toast for 8 to 10 minutes, until fragrant and the cashews are golden. Let cool.
Meanwhile, in a large skillet, heat 1/4 inch of olive oil until shimmering. Add the garlic and cook over moderate heat, stirring, until golden and crisp, about 5 minutes. Using a slotted spoon, transfer the crispy garlic to paper towels to drain. Carefully add the rosemary and sage to the skillet and cook until the sizzling slows and the herbs are crisp, about 30 seconds. Using a slotted spoon, transfer to paper towels to drain.
Pour off all but 2 tablespoons of the garlic-herb oil from the skillet. Add the toasted nuts along with the pistachios and almonds and cook over moderate heat, tossing and stirring frequently, until the nuts are warm and coated in the oil, 1 to 2 minutes. Season generously with salt and pepper, then fold in the crispy garlic and herbs. Transfer to a medium bowl and serve warm or at room temperature.