Soak the dried black beans and red kidney beans overnight in separate bowls with plenty of water.
The next day, drain and rinse the soaked beans. In a large pot, cover the beans with fresh water and bring to a boil. Reduce heat and simmer for about 45 minutes or until tender. Drain and set aside.
Heat the Instant Pot on sauté mode. Add the teaspoon of olive oil and allow it to warm up for about 30 seconds.
Add the minced garlic and sliced onions to the pot. Sauté for 3-4 minutes, stirring occasionally, until the onions begin to soften and become translucent.
Add the diced red bell pepper and chopped red chili pepper. Continue to sauté for another 2-3 minutes, until the peppers start to soften.
Push the sautéed vegetables to the sides of the pot, creating a clear space in the center.
Add the ground beef to the center of the pot. Break it up with a wooden spoon and add the dried oregano, ground cumin, paprika, and salt. Cook the beef, stirring occasionally, until it's browned and no longer pink, about 5-7 minutes.
Once the beef is cooked, stir to combine it with the sautéed vegetables.
Add the cooked black beans, red kidney beans, green beans, corn kernels, and tomato paste to the pot. Stir gently to combine all ingredients.
Pour in the beef broth, making sure to scrape the bottom of the pot to release any browned bits.
Stir everything together to ensure all ingredients are well combined.
Cook: Close the Instant Pot lid and set the valve to sealing position. Cancel the sauté mode and set the Instant Pot to manual high pressure for 10 minutes.
Depressurize: Once the cooking cycle is complete, allow the pressure to naturally release for 10 minutes, then carefully perform a quick release for any remaining pressure.
Open the lid and stir the soup gently to combine all ingredients evenly.
Taste and adjust seasoning if necessary.
Serve: Ladle the hot Cowboy Casserole Soup into bowls and serve immediately.