Slice your chicken breasts in half lengthwise to make thinner cutlets. Generously season them with salt & pepper on both sides, and sprinkle the garlic powder on both sides evenly. Dredge them in flour.
In a large skillet over medium-high heat, melt the butter and olive oil. When the pan's hot, add the chicken and cook it for 4-5 minutes per side, until golden. Take the chicken out of the pan and set it aside.
Add the chicken broth and lemon juice to the pan, and let it cook for about a minute (make sure to scrape up the brown bits at the bottom of the pan).
Add the chicken back into the pan and pour the cream over top. Let the sauce simmer for 5 minutes or so, until the cream thickens up a bit and the chicken is cooked through completely.
Before serving, I like to grate some lemon zest and stir it into the sauce, but this is totally optional. Add more salt & pepper if needed and sprinkle parsley over top if using. Serve immediately.
You could swap the chicken broth with dry white wine if desired.
I don't recommending swapping the cream for half-and-half or milk because the lemon juice may cause it to separate.