If starting with chicken breasts, slice them in half through the thickness to form 4 cutlets. (If you're starting with 4 cutlets, no need to cut them further.) Season on all sides with onion powder and pepper. Don't add salt at this point.
In a heavy-bottomed skillet, warm the olive oil over medium heat. Brown the cutlets on both sides, about 7-8 minutes total. Remove the cutlets to a plate.
Add the wine to the skillet, stirring up any browned bits. Turn the heat to low. Add the tomatoes, Boursin, and basil to the skillet, stirring frequently until the boursin is melted.
Return the cutlets to the pan along with any collected juices. Spoon the sauce over the chicken and continue to cook until chicken is hot. Taste for salt and pepper and adjust if needed.
