Slice the boneless skinless chicken breasts in half lengthwise.
In a shallow bowl, mix the flour, salt, and pepper. Then, dredge both sides of the chicken cutlets in the flour mixture.
Lightly spray a pan with olive oil over medium heat and add the chicken cutlets to the pan. Sear the chicken on both sides, about 3-4 minutes per side, depending on the thickness of the chicken. Once seared, remove the chicken from the pan and let it rest. Keep in mind that the chicken will finish cooking later when it is placed back in the pan with the simmering sauce.
Add the milk, cottage cheese, grated parmesan cheese, salt, and pepper to a blender and blend until smooth.
Add the light butter to the pan along with the diced onion. Saute the onion in the butter until translucent. Then, add the crushed garlic and one teaspoon of fresh chopped parsley to the pan. Save the rest of the parsley to sprinkle on top once done. Saute the garlic and parsley in the pan.
Add the blended mixture to the pan and mix. Optional: To thicken the sauce even more, add a cornstarch slurry to the pan by mixing 1 ½ teaspoons of cornstarch and 1 ½ teaspoons of cold water.
Add the chicken back to the pan with the sauce. Let the sauce and chicken simmer on medium-low heat with the lid off for 10-12 minutes or until the chicken is fully cooked and reaches an internal temperature of 165℉. Simmering the sauce will allow it to thicken, intensify, and have a creamy consistency.
Once the chicken is fully cooked and the sauce is finished simmering, serve this dish on plates. Add the remaining tablespoon of freshly chopped parsley on top and enjoy this dish warm! Optional: Grate some parmesan cheese over top of the chicken.