To a large pot or Dutch oven, heat the olive oil over medium heat. Add the onion, sprinkle with ¼ teaspoon salt, and cook, stirring occasionally, until it begins to soften, about 3 minutes.
Add the carrot and celery, stirring to combine. Sprinkle with ¼ teaspoon salt and the garlic powder, then cook for an additional 3-5 minutes until slightly softened, stirring occasionally.
Add the tomato paste, stirring until fragrant, about 1 minute.
Add the potatoes, diced tomatoes, bay leaf, remaining 1 teaspoon salt and chicken, stirring to combine.
Add the stock, cover, bring to a boil, then reduce to a simmer. Cook, covered, for 15-25 minutes until the potatoes are tender and the chicken is cooked through.
Uncover and remove the chicken to a cutting board. Add the green beans to the pot, and stir.
Shred chicken with two forks, or chop into bite-sized pieces.
Turn off the heat, then add back the chicken, along with adding the corn and peas, stirring to combine. Taste and add additional salt if desired.