Slice each chicken breast horizontally to create four thin cutlets total. Pat them completely dry with paper towels. In a shallow dish, mix together the flour, salt, pepper, paprika, onion powder, and dried thyme. Dredge each chicken cutlet in the seasoned flour mixture, shaking off any excess.

Heat the olive oil and 1 tablespoon of butter in a large skillet over medium-high heat until the butter is melted and hot but not smoking. Add the chicken cutlets in a single layer, working in batches if necessary. Cook for 5 to 6 minutes on the first side without moving them. Flip and cook for another 5 to 6 minutes until golden and the internal temperature reaches 165°F. Remove to a plate and tent with foil.

Reduce heat to medium and add the remaining 1 tablespoon of butter to the same skillet. Once melted, add the minced garlic and cook for about 30 seconds, stirring constantly until fragrant but not browned.

Pour in the chicken stock and use a wooden spoon to scrape up all the browned bits stuck to the bottom of the pan. Let the stock simmer for 1 to 2 minutes until reduced by about half.

Stir in the heavy cream and Dijon mustard, mixing until well combined. Let the mixture simmer gently over medium heat for about 2 minutes, stirring occasionally, until it starts to thicken slightly.

Remove the pan from the heat and stir in the grated Parmesan cheese, whisking until it melts completely and the sauce becomes smooth. Taste and adjust seasoning with additional salt or pepper if needed.

Return the chicken cutlets and any accumulated juices from the plate back to the skillet. Spoon the sauce over the chicken and let everything simmer together for 2 to 3 minutes over low heat.

Transfer chicken to serving plates, generously spooning the creamy garlic sauce over each piece. Garnish with chopped fresh parsley and serve with lemon wedges on the side.