Preheat oven to 400 F. Make sure the butternut squash is peeled, seeded, and cubed. Here is a very detailed recipe on how to peel, seed, cube, and roast butternut squash.

In a large bowl, toss cubed butternut squash with olive oil, salt, and pepper.

Spread the squash on a parchment paper-lined baking sheet in one layer, without overcrowding.

Roast on the middle rack in the preheated oven at 400 F for about 30 minutes. Remove from oven.

Preheat oven to 400 F. Trim ends of Brussels sprouts and remove yellow leaves. Slice all Brussels sprouts in half.

In a medium bowl, toss Brussels sprouts with olive oil, salt, and pepper.

Spread the Brussels sprouts on a parchment paper-lined baking sheet in one layer, without overcrowding.

Roast on the middle rack in the preheated oven at 400 F for 20 or 30 minutes. You can roast them at the same time you roast butternut squash. Remove from oven.

Season the flank steak on both sides with ¼ teaspoon of smoked paprika, ¼ teaspoon of chili powder, and season generously with salt and freshly ground black pepper. You can use more than ¼ teaspoon of salt.

Heat an empty large cast-iron skillet over medium heat for 2 minutes. This allows the cast-iron skillet to heat through. Add 2 tablespoons of olive oil. Add the whole flank steak and cook on medium heat for 5 minutes, without moving it at all so that it sears nicely.

Flip the flank steak over to the other side, reduce heat to low-medium, and cook for about 5 minutes or more until the steak is cooked to your liking. As a guidance, the meat thermometer should register 130°F for medium-rare, and 145°F for medium in the thickest part of the steak (FDA-recommended safe internal cooking temperature for steak is 145°F).

Remove the steak from the skillet to a plate. Slice the steak against the grain into thin strips about 1-inch wide.

To the same, now empty, cast-iron skillet, add butter and minced garlic. Cook on low-medium heat for about 1 or 2 minutes or until the garlic softens.

Add cooked and sliced flank steak, fresh thyme, and coat thoroughly with the garlic butter sauce on low-medium heat for a minute or two. Remove from heat.

Add roasted butternut squash and roasted Brussels sprouts to the skillet with a cooked flank steak to warm everything up on low heat. If you used a large skillet, everything should fit. If not, work in batches. Top with more fresh thyme. Season with salt and freshly ground black pepper to taste.