Line a small baking sheet with parchment paper and set aside.Set a small skillet over medium heat. Add 1 cup unsalted walnut halves, and toast just until fragrant, about 2 - 3 minutes. Stir in 1 tablespoon unsalted butter, 3 tablespoons maple syrup, 1 teaspoon Aleppo pepper, and ¼ teaspoon Diamond-Crystal Kosher Salt. Cook, stirring, until the syrup is bubbly, reduced, and coats the nuts, 2 - 3 minutes.Spread the nuts evenly on the parchment-lined baking sheet. Season with another pinch of salt, and refrigerate for 10 minutes to cool completely. If there are any clumps, make sure to break the nuts into bite-sized pieces.
For the salad:
Prepare the greens: Tear 3 ounces butter lettuce and 4 ounces radicchio into bite-sized pieces, leaving any smaller leaves intact. This yielded about 5 cups packed greens. Transfer to a large serving bowl and season with a pinch of salt. Add 1 Granny Smith apple, cored and thinly sliced, ¼ cup hand-crumbled Gorgonzola cheese, and ½ cup spiced maple walnuts. Set aside while you prepare the dressing.Note: Leftover walnuts can be snacked on or stored in an airtight container for up to 1 week at room temperature.
Make the dressing: In a small sealable jar, combine 1 teaspoon stone-ground mustard, the juice of ½ lemon, apinch of salt and black pepper, and 2 tablespoons extra-virgin olive oil. Shake vigorously until the dressing is nicely emulsified; it should look pale yellow and slightly creamy. Tip: Before serving, make sure the dressing is seasoned appropriately. To do so, dip a piece of radicchio in the dressing. Taste, and adjust seasonings as desired. Too acidic? At some more oil. Too bland? Add a bit more lemon juice, mustard, or salt.
Serve: Toss the salad with the dressing, and serve immediately. Enjoy!
Notes
* Radicchio can vary considerably in size, so if possible, I highly recommend using a scale to weigh all of the greens!Maple syrup: For a sweeter, stickier candied walnut, use ¼ cup maple syrup.The spiced maple walnuts yield about 1 cup, while the salad uses about half. We found them so addicting that we wanted extras to snack on! But they'd also be great with roasted brussels sprouts, yogurt bowls, or ice cream too.