1. Preheat the Oven and Prep the Squash Set your oven to 400°F and position a rack in the center. Line a large baking sheet with parchment paper. Place the peeled, cubed butternut squash in a mixing bowl, drizzle with 1 tablespoon of the olive oil, and season with a generous pinch of salt and pepper. Toss until every cube looks lightly coated and glossy.

2. Roast the Butternut Squash Spread the squash across the prepared baking sheet in a single, even layer, leaving a little space between the cubes so they roast instead of steam. Roast for 30 minutes, stirring once around the halfway point, until the squash is tender when pierced with a fork and the edges have turned golden and lightly caramelized.

3. Prep and Roast the Brussels Sprouts While the squash roasts, toss the halved Brussels sprouts in a clean bowl with 1 tablespoon of olive oil, salt, and pepper. Arrange them on a second baking sheet, cut-side down, in a single layer without crowding. Roast for 20 to 30 minutes, until the sprouts are deeply golden brown, tender in the center, and crisp around the outer leaves. If both pans don’t fit on one rack, place them on separate racks and swap their positions partway through for even browning.

4. Boil the Tortellini Bring a large pot of generously salted water to a full rolling boil. Add the cheese tortellini and cook according to the package directions, usually just a few minutes, until the pasta floats and is al dente, tender but still with a slight bite. Drain the tortellini well in a colander and set it aside. Don’t rinse it, and keep it ready to combine later. Pulling it slightly early is smart, since the pasta will soften a little more when tossed with the hot sauce.

5. Slice and Season the Chicken Pat the chicken thighs dry with paper towels, since surface moisture prevents browning. Slice the chicken into thin strips and place them in a bowl. Sprinkle with the smoked paprika, salt, and black pepper, then toss until every strip is evenly seasoned.

6. Heat the Skillet Set a large cast-iron skillet over medium heat and let it warm for a full 3 minutes so the pan holds steady, even heat. A properly heated skillet is what gives the chicken a golden crust instead of a pale, steamed surface.

7. Sear the Chicken Add the remaining 1 tablespoon of olive oil to the hot skillet and swirl to coat the bottom. Lay the chicken strips in a single layer, without overlapping or crowding them. Cook undisturbed for 4 minutes so a golden crust forms on the underside. Flip each piece and continue cooking until the chicken is fully cooked through with no pink remaining, a few more minutes depending on thickness. Transfer the chicken to a clean plate and set it aside.

8. Make the Garlic Butter Sauce Lower the heat to low-medium and return to the same skillet, leaving the browned bits on the bottom since they add flavor. Add the butter and let it melt gently. Stir in the minced garlic and sauté for 1 to 2 minutes, stirring often, until the garlic turns fragrant and soft. Be careful not to burn the garlic, since burnt garlic turns bitter and would spoil the whole sauce. If the pan seems too hot, pull it off the heat for a moment.

9. Toss the Tortellini in the Sauce Add the drained tortellini to the skillet with the garlic butter. Toss gently with a spatula or large spoon until every piece is coated in the glossy, fragrant sauce.

10. Combine and Finish Return the seared chicken to the skillet, along with any juices that collected on the plate. Gently fold in the roasted butternut squash and Brussels sprouts, taking care not to break up the squash. Sprinkle the fresh thyme over the top and taste. Adjust with a pinch more salt and pepper if needed.

11. Serve Serve immediately, straight from the skillet or portioned onto warm plates, while the vegetables are still crisp and the sauce is silky.