Wash and chop vegetables (except for the spinach) into small bite-sized pieces, then place them on a large sheet pan with edges or in a baking dish. (You can use 4-5 cups of any vegetable that you wish.)
Drizzle the vegetables with olive oil and sprinkle with a bit of salt, then place them in 400°F (204°C) oven for 20 minutes. Flip them, then bake for another 10 minutes before adding the dressing.
While the veggies are baking, make your dressing by combining 1/2 cup olive oil, 1/2 cup balsamic vinegar, 1/3 cup maple syrup, 1 tsp salt, and 1/2 tsp garlic powder.
After the vegetables have roasted for 30 minutes, pour the dressing over them and return them to the oven for an additional 10 minutes. (Totaling 40 minutes of baking time.)
Add 2 cups of baby spinach to the bottom of a large mixing bowl.
Boil the orzo pasta in salted water for 10 minutes, then drain and rinse. Then pour it over the baby spinach immediately so that the heat of the orzo wilts the spinach.
After the vegetables have roasted for 40 minutes, pour them over orzo and spinach along with all the liquid from the dressing and mix well.
Add 1/4 cup of toasted pine nuts (optional) and or pomegranate seeds to the salad for extra flavor and a little crunch. You can also serve these on the side for those who don't want nuts.
Notes
If you don't have a large sheetpan with high edges, use a baking dish to roast the veggies. You will add about 1 1/2 cups of dressing towards the end of baking, and you don't want it to spill out.
I find that a metal sheetpan or baking dish makes the roasted veggies a little crispier.
It is essential to add the dressing to the roasting veggies to cook down the balsamic and mellow out the flavor.