Preheat your oven to 425°F. Line a baking sheet with parchment paper or lightly oil it.

Spread the diced butternut squash on the prepared sheet in a single layer. Drizzle with olive oil, season with salt and pepper, and toss to coat evenly.

Roast for 25 to 30 minutes, stirring halfway through, until the squash is tender and lightly caramelized. Set aside.

Season the chicken thighs on both sides with 3/4 teaspoon salt and 1/2 teaspoon pepper.

In a Dutch oven or large heavy pot, melt the butter over medium heat. Working in batches if needed, add the chicken in a single layer and cook until golden brown and cooked through (internal temperature of 165°F), about 4 to 5 minutes per side. Transfer the chicken to a plate and set aside.

Add the diced shallot to the pot and cook, stirring occasionally, until softened, about 2 to 3 minutes. Stir in the garlic, thyme, and sage and cook until fragrant, about 1 minute.

Whisk in the flour and cook, stirring constantly, until lightly browned, about 1 minute.

Pour in the chicken stock and Dijon mustard, scraping up any browned bits from the bottom of the pot. Stir in the orzo and season with salt and pepper to taste.

Bring the mixture to a boil, then reduce the heat to a simmer. Cook, stirring occasionally, until the orzo is tender, about 6 minutes.

Add the chopped kale, Parmesan, and heavy cream. Stir until the kale has wilted, about 3 minutes.

Gently fold in the roasted butternut squash. Taste and adjust seasoning with salt and pepper if needed. Return the cooked chicken to the pot, nestling it into the orzo.

Serve immediately, spooning the creamy orzo and squash onto plates and topping with the chicken.