In a mixing bowl, combine the warm water and yeast. Let it sit for about 5 minutes until it becomes frothy. This activates the yeast.

In another bowl, mix the flour and salt. Create a well in the center and add the yeast mixture and olive oil.

Stir until a dough forms. Transfer to a floured surface and knead for about 5-7 minutes until smooth and elastic.

Place the dough in a lightly oiled bowl, cover with a damp cloth, and let it rise in a warm place for about 30 minutes, or until doubled in size.

Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.

In a bowl, toss the halved Brussels sprouts with olive oil, balsamic vinegar, honey, garlic powder, salt, and pepper.

Spread the Brussels sprouts on the prepared baking sheet in a single layer. Roast for 20-25 minutes, or until golden and tender, stirring halfway through.

While the Brussels sprouts are roasting, heat a skillet over medium-high heat. Season the flank steak with salt and pepper.

Add a tablespoon of olive oil to the skillet. Once hot, add the steak and sear for about 4-5 minutes on each side for medium-rare, or until it reaches an internal temperature of 135°F (57°C).

Remove the steak from the skillet and let it rest for 5 minutes before slicing it thinly against the grain.

Preheat the oven to 450°F (232°C). Roll out the risen dough on a floured surface to your desired thickness.

Transfer the rolled dough to a baking sheet or pizza stone. Brush lightly with olive oil.

Spread the goat cheese evenly over the flatbread, then layer the sliced steak and roasted Brussels sprouts on top.

Bake in the preheated oven for 10-12 minutes, or until the edges are golden and the cheese is slightly melted.

Remove the flatbread from the oven and let it cool for a couple of minutes. Slice into pieces and serve warm.