Step 1

Prepare and preheat grill.

Step 2

If any of your zucchini or yellow squash rounds are very large in diameter, you can cut those rounds in half to yield smaller semi-circles. In a medium bowl, combine yellow squash, zucchini, and onion with olive oil, 1 teaspoon rosemary, salt, and black pepper. Toss well until the mixture is thoroughly combined and the vegetables are evenly coated all over with oil and seasonings.

Step 3

Spread vegetable mixture in an even, single layer on a grill topper that's large enough that the vegetables don't have to overlap too much (ours is about 11" x 14").

Step 4

Grill vegetables over medium heat for about 15 minutes, stirring about every 5 minutes. You want the vegetables to develop areas of seared brown grill marks, without becoming too mushy or burned.

Step 5

Meanwhile, spray both sides of each flatbread lightly with nonstick spray. Grill over medium heat for 2 minutes on each side, until they develop lightly browned grill marks.

Step 6

Top grilled flatbreads with grilled vegetables, and sprinkle evenly with goat cheese and remaining 1/2 teaspoon rosemary. Lightly and evenly drizzle balsamic vinegar over top, if desired.

Step 7

Cut into wedges and serve immediately.