Season the liver with a teaspoon of salt, pepper, oregano and garlic.
In a pot heat the oil over medium heat.
Add liver, cook until brown on both sides (about 2 minutes each side). Add the peppers, and onions. Cook and stir for 5 minutes or until onion becomes translucent.
Remove from the heat and serve immediately.
Notes
For tender liver, do not overcook. Otherwise, it’ll turn tough and rubbery.