Because this dish comes together so quickly, it is a good idea to prep everything in advance. That means cutting the chicken into strips, draining and rinsing the beans, opening the tomatoes, and washing the spinach.
Slice the chicken breast into about 1/2 inch strips.
Heat one tablespoon of olive oil in a deep skillet over medium high heat.
Add the chicken to the hot skillet and lightly salt.
Cook the chicken stirring and flipping the pieces until cooked through, about 5 minutes. You can add an additional tablespoon of olive oil if you feel the pan is too dry.
Carefully add the undrained tomatoes, the beans, and the oregano.
Stir the mixture and allow it to heat, about four minutes.
Slowly pour in the heavy cream in a steady stream, stirring constantly. Stirring the cream this way will keep it from curdling.
Stir in 1/2 cup shredded Parmesan cheese.
Let the whole thing heat over medium heat for about four minutes.
Pour the spinach over the top and cover. There will be a big pile of spinach on top, but it cooks and reduces pretty quickly.
Let the spinach completely wilt, about five minutes. As most of the leaves shrink down, stir everything together one last time.
Add salt to taste.