Ramen with frozen vegetables mixed in.
I like to add soy protein chunks (TVP) in my instant noodles too. They’re one of the cheapest sources of protein and do not need any extra work as long as you get the small ones. Just dump it in with the hot soup and wait for it to rehydrate.
How much of a concern is arsenic? A lot of Asian cultures have rice with every meal and they have some of the healthiest people on the planet.