Slice each chicken breast in half lengthwise to create four thin cutlets.
Season both sides with garlic powder, salt, and black pepper.
Lightly dredge each cutlet in flour, shaking off any excess.
Heat the olive oil and butter in a large skillet over medium-high heat.
Add the chicken and cook for 4–5 minutes per side until golden brown. Transfer the chicken to a plate.
Reduce the heat to medium and add the minced garlic to the same skillet. Cook for about 30 seconds until fragrant.
Stir in the Dijon mustard and chicken broth, scraping up the browned bits from the bottom of the pan.
Pour in the heavy cream and stir until smooth.
Add the chopped tomato, Italian seasoning, and fresh basil.
Bring the sauce to a gentle simmer.
Return the chicken to the skillet and spoon the sauce over each piece.
Simmer for another 5–7 minutes until the chicken reaches an internal temperature of 165°F (74°C) and the sauce thickens slightly.
Taste and adjust with additional salt and pepper if needed.
Serve the Creamy Tomato Basil Chicken immediately with your favorite side dishes.