Instant Pot Hodgepodge Soup to Share with Work Colleagues

I wanted to make a big batch of soup to take to a lunch meeting at work yesterday, but I wanted it to be easy and to make use of whatever odds and ends I had in the vegetable bin and pantry. I came up with the following, and my co-workers raved. I didn't have the heart to tell them it was just a crazy hodge-podge that I made up as I went along. (But a tasty hodgepodge nevertheless!)

Instant Pot Italian Chicken, Veggie and Wild Rice Soup

1 1/2 cups wild rice, barley, and dried veggie* mix
8-12 cups homemade chicken broth, divided
2 large stalks celery, diced
1 large onion, diced
4 cloves garlic, minced
2 large frozen boneless/skinless chicken breasts, cubed
1 15 oz. can diced tomatoes (with garlic and onions)
2 tablespoons white balsamic vinegar
1 tablespoon vegetable soup base (Better Than Bouillon), or more to taste
1 tablespoon dried Italian herbs
2 sprigs fresh rosemary
2 bay leaves
1 teaspoon poultry seasoning
1/2 teaspoon black pepper
pinch of red pepper flakes
four handfuls of fresh spinach (or chopped kale)

*The soup mix I used had carrots in it, otherwise, I would have diced some fresh carrots to add in at the same time as the celery and onion and all.

Pressure cook the wild rice mix in four cups of chicken broth on Manual/high for 20 minutes. Add all of the other ingredients including another four cups of chicken broth, but not the spinach. Cook on Manual/high for another five minutes. Thin with more broth, remove the rosemary stems and bay leaves, correct seasonings, and stir in the spinach just before serving.