This recipe is a great weeknight meal because most of the ingredients are already in your pantry. Chop the vegetables while you get nice color on the chicken. Then bring the water to a boil and cook the pasta while the sauce simmers. If you multitask, it all comes together in about 30 minutes.
Sprinkle the chicken with salt and pepper. Heat a high-sided pan over medium-high heat, and then add 1 tablespoon of the olive oil. Sear the chicken on both sides until browned, but not cooked all the way through.
Bring a large pot of salted water to a boil.
Set the chicken aside and add the remaining tablespoon of olive oil to the pan, and then add in the tomato paste, garlic, and onions. Cook until the onions are translucent and the tomato paste turns brick red, about 5 minutes. Add in the mushrooms and cook for 5 minutes.
When the water comes to a boil add in the pasta and cook according to package directions.
Add in the tomatoes and oregano, and cook until slightly crushed. Pour in some wine and bring to a simmer. Season the sauce with salt and pepper. Add the chicken back to the pan along with the capers, and simmer until the chicken is cooked through and the sauce thickens up, about 20 minutes.
Toss the pasta with the tomato sauce and serve with the chicken. Top with a bit of cheese, if using.