Season steak with salt and pepper. Heat oil in large heavy pot over medium high heat. Add steak and cook until all browned and then remove meat to a plate.
If needed, add more oil to the pot and add the onions. Cook onions over medium heat until they begin to soften. Stir in the green, red and jalapeño peppers and cook for about 3 to 5 minutes. Add the garlic, chili powder, cumin and oregano.
Return the browned meat to pot and pour in the beef stock. Bring to a boil and cover and reduce heat to a simmer. Cook for 20 to 25 minutes or until meat is tender. Add in the crushed tomatoes and cook another 20 minutes. Stir in black and kidney beans and gently simmer for 10 minutes.
Ladle chili into bowls and garnish with cheddar cheese, scallions and sour cream if desired. Enjoy!