Sheet-Pan Baked Feta with Broccolini, Tomatoes and Lemon

Ingredients

• 1 bunch broccolini, ends trimmed, thick stalks split lengthwise, or broccoli, stalks trimmed and cut into bite-size pieces
• 1 pint grape tomatoes, halved (about 2 cups)
• 1 small red onion, peeled, quartered and cut into 2-inch wedges
• 1 lemon, 1/2 cut into thin rounds and the remaining 1/2 left intact, for serving
• 3 tablespoons olive oil, plus more for serving
• 1 teaspoon ground cumin
• ½ teaspoon red-pepper flakes
• Kosher salt and black pepper
• 2 (6- to 8-ounce) blocks feta, cut into 1-inch slices
• Cooked orzo or farro, for serving
• ½ cup fresh basil or cilantro leaves and fine stems, roughly chopped (optional)