I start by preheating my oven to 400°F and lining a baking sheet with parchment paper. This step matters more than people think, since a properly heated oven is what gives the pears that gorgeous caramelized edge instead of a soggy, steamed texture.
Next, I slice each pear in half lengthwise and use a melon baller to scoop out the seeds and tough core. I brush the cut sides with lemon juice right away so they don't brown while I finish prepping the rest.
In a small bowl, I whisk together the melted butter, honey, cinnamon, nutmeg, and a pinch of salt until it's smooth and glossy. This glaze is really the heart of the recipe, so I always taste it before brushing it on.
I place the pear halves cut-side up on the baking sheet, spacing them a couple of inches apart so they roast instead of steam. Then I generously brush the honey mixture over each one, letting a little pool in the center.
I roast the pears for about 25 to 30 minutes, basting them once halfway through with the pan juices. They're done when they're fork-tender and the edges have turned a deep caramel color.
Once out of the oven, I sprinkle the warm pears with chopped walnuts and let them rest for a couple of minutes. This little pause lets the glaze thicken slightly before serving.