Bring a large pot of water to a rolling boil and season heavily with salt. Cook pasta according to manufacturer instructions until al dente. Reserve 0.5 cup of the starchy cooking water, then drain the pasta.
While pasta cooks, season the cubed chicken with salt, black pepper, and dried oregano.
Heat olive oil in a large skillet over medium-high heat. Add the chicken in a single layer and sear until golden brown and the internal temperature reaches 165°F (74°C), approximately 6-8 minutes. Remove chicken from the pan and set aside.
Reduce skillet heat to medium. Add the minced garlic to the remaining oil and sauté for 60 seconds until fragrant, ensuring the garlic does not burn.
Pour the heavy cream into the skillet, scraping the bottom of the pan to deglaze the browned bits (fond). Bring to a light simmer for 2-3 minutes.
Gradually whisk in the grated Parmesan cheese until fully melted and the sauce has thickened.
Return the cooked chicken to the skillet and add the cooked pasta. Toss vigorously to coat.
If the sauce is too thick, gradually add the reserved pasta water 1 tablespoon at a time until the desired consistency is achieved.
Garnish with fresh parsley and serve immediately.