• Adjust rack to top position (top and middle positions for 4 servings). Place a baking sheet on top rack and preheat oven to 450 degrees. Wash and dry all produce. • Halve, peel, and thinly slice onion. Dice squash into 1/4-inch pieces. Strip 2 tsp thyme leaves from stems; roughly chop leaves.

• Melt 1 TBSP butter (2 TBSP for 4 servings) in a medium pan over medium heat. Add onion; cook, stirring occasionally, until browned and softened, 8-10 minutes. TIP: If onion begins to brown too quickly, add a splash of water. • Stir in 1 tsp sugar and 1 tsp balsamic glaze (save the rest for serving). (Use 2 tsp balsamic glaze for 4.) Cook until caramelized and jammy, 2-3 minutes more. Season with salt and pepper. Turn off heat.

• While onion cooks, carefully toss squash on prepared baking sheet with a drizzle of oil, half the chopped thyme, salt, and pepper. Roast on top rack until tender and lightly browned, 10-12 minutes. • Transfer to a medium bowl; set aside.

• Meanwhile, in a small bowl, combine ricotta, remaining chopped thyme, and 2 tsp olive oil (3 tsp for 4 servings). Season with salt and pepper.

• Lightly oil baking sheet used for squash. Place flatbreads on sheet. (For 4 servings, divide flatbreads between 2 lightly oiled sheets.) • Evenly spread flatbreads with ricotta mixture, then top with caramelized onion, squash, and mozzarella.

• Bake flatbreads on top rack until edges are golden brown and cheese has melted, 10-12 minutes. (For 4 servings, bake on top and middle racks; swap rack positions halfway through baking.) • Transfer to a cutting board and drizzle with remaining balsamic glaze to taste. • Slice into pieces, divide between plates, and serve.