1.First, bring a large pot of water to a boil. In a serving bowl, add the lemon juice, 1 tablespoon of the olive oil, salt and pepper. Whisk to combine. Set aside.When the pasta is boiling, add a handful of salt and the orzo pasta. Cook the orzo according to the package directions. Drain and add to bowl. .
2. Meanwhile, chop the veggies into large chunks for the grill: slice the pepper in quarters, slice the squashes in half length-wise, and slice the onion into 2 or 3 slabs.
3. Preheat a grill over high heat. Drizzle olive oil in the pan, and then arrange the veggies in the pan. Cook for 5 minutes, check for grill marks and flip, and then cook on the second side until more grill marks form. Remove the veggies from the grill, and let cool slightly.
4. Chop up the grilled veggies into bite-size pieces, and add the serving bowl. Toss everything together very well, and then garnish with chopped fresh parsley. Serve warm or at room temperature.