Roast the Tomatoes : Preheat your oven to 425°F (220°C). Tumble the cherry tomatoes onto the baking sheet and drizzle with 1 tablespoon of olive oil. Season lightly with salt and pepper. Roast for 12–15 minutes, until the skins just begin to split and soften.
Prepare the Vegetables : While the tomatoes are in the oven, prepare your other vegetables. Dice the English cucumber and yellow bell pepper, halve the Kalamata olives, and finely dice the red onion. Place everything in the large mixing bowl.
Whisk the Vinaigrette : In a small bowl or jar, whisk together the remaining 2 tablespoons of olive oil, the white balsamic vinegar, dried dill, and optional red pepper flakes. Set this simple dressing aside to allow the flavors to meld.
Toast the Orzo : Place the Dutch oven over medium heat. Add the dry orzo and toast for about 3 minutes, stirring frequently, until it turns a light golden-brown and smells nutty. This step adds a wonderful depth of flavor.
Cook the Pasta : To the toasted orzo, carefully pour in 8 cups (2 L) of water and a generous pinch of salt. Bring to a rolling boil and cook for 8–10 minutes, or until the pasta is tender with a slight bite (al dente).
Drain and Cool : Pour the cooked orzo into a colander and immediately rinse with cool running water to stop the cooking process and wash away excess starch. Shake well to remove as much water as possible.
Assemble the Salad : Add the cooled orzo to the large bowl with the chopped vegetables. Pour the vinaigrette over the top, add the crumbled feta, and gently fold everything together. Once the roasted tomatoes are cool enough to handle, add them to the salad. Season generously with salt and pepper to your preference.
Garnish and Serve : Garnish the salad with the chopped fresh dill just before serving. This dish can be enjoyed immediately or chilled for later.