Press the saute function in a 6 or 8 quart Instant Pot and add olive oil. Once hot, add onion and garlic and cook until beginning to soften, about 5 minutes. Add in tomato paste, oregano, salt and pepper and cook for 30 seconds. Add in diced tomato, chicken breasts and broth and stir together. Shut off the saute function.
Close the lid and set the pressure-release valve to sealing. Cook soup on manual high pressure for 9 minutes with a quick release. Remove chicken, dice to bite-sized pieces and cover to keep warm while the pasta cooks.
Press the saute function on the Instant Pot and add in 1 cup of water. Once boiling, add the pasta and cook according to package instructions.
Meanwhile, toast the breadcrumbs: Heat oil in a small pan over medium heat. Add pecans, italian seasoning and garlic powder. Cook stirring occasionally until the pecans smell toasted, about 3-5 minutes.
Once the pasta has finished cooking, place the diced chicken back in the pot. If needed, add remaining cup of water to thin out the soup.
Serve the soup with a garnish of parmesan cheese, “breadcrumbs” and parsley.