Prepare the chicken: Slice each chicken breast horizontally through the middle to create two thin cutlets. You should have 8 pieces total. Season both sides with salt, pepper, and garlic powder. The seasoning will look speckled against the pale chicken flesh.

Set up your dredging station: In a shallow bowl, whisk the eggs until they're a uniform pale yellow, with no streaks of white remaining. In a separate shallow bowl, spread the flour in an even layer. Have a large plate ready nearby to hold the coated chicken.

Coat the cutlets: Take one piece of chicken and dredge it in the flour, pressing gently so the flour adheres. Shake off any excess — you want a light, even dusting, not a thick clump. Then dip it into the beaten egg, letting any excess drip back into the bowl. The coated cutlet should look glossy and golden, with the flour just visible beneath the egg.

Fry to golden perfection: Heat the olive oil in a large frying pan over medium-high heat. When the oil shimmers and a small pinch of flour sizzles immediately on contact, it's ready. Carefully place 2-3 cutlets in the pan, making sure not to overcrowd them. Fry for 3-4 minutes per side. The edges will turn a deep golden brown, and the crust will feel firm and crisp when you gently press it with a spatula. The sizzling sound will be lively and steady. Transfer the cooked cutlets to a paper-towel-lined plate and repeat with the remaining chicken.

Build the lemon sauce: Reduce the heat to medium-low. Add the butter to the same pan, scraping up any browned bits from the bottom with a wooden spoon. The butter will melt and foam gently, releasing a nutty, rich aroma. Pour in the chicken stock and lemon juice, then add the lemon zest. Stir everything together, and let the sauce simmer for 2-3 minutes. It will thicken slightly and turn a pale, translucent yellow, with small bubbles breaking the surface.

Return the chicken to the pan: Gently place the fried cutlets back into the sauce, spooning some of the liquid over the tops. Let them warm through for 1-2 minutes. The crust will soften just slightly on the bottom while staying crisp on top, and the sauce will cling to the chicken in a glossy, thin coating.

Finish and serve: Sprinkle the chopped fresh parsley over the top, and garnish with lemon slices if desired. Serve immediately while the chicken is still warm and the sauce is silky. The final dish should look vibrant: golden chicken nestled in a pale yellow sauce with flecks of green parsley.