Cook potato in little water in microwave until fork tender.
Heat 2 tsp olive oil in a sauté pan, add the onions and cook until translucent, about 5 minutes. Add all the frozen veggies along with the potatoes (drained) and cook on medium high until the edges start to brown.
Add cumin, chili powder, salt, pepper and orzo. Mix well and let the flavors mingle for a couple of minutes.
Add miso paste mixed in 2tsp water to orzo and cook for another 2 minutes. Serve warm.