I live in the south, but for what you are requesting, I say go to Burgundy for the wine sauces, cream sauces, cheeses, pastry, eggs, even the honey. The whole area, sweeping east to west from the Jura across Burgundy to the Loire Valley has the quintessential dishes and many, many interesting wines.
When you write entrées, you mean main dishes because in France an entrée is the first course.
Good ripe fruits, vegetables can be found nearly anywhere. In the south, we use tomato base, olive oil and wine for our sauces, while it’s the cream, butter and wine in the north. For two or three weeks, that rich cuisine is a special indulgence.
Lyon is mentioned above. You have to be careful there because it’s known not only for Paul Bocuse, but also a cuisine specializing in organ meats, and a hearty unrefined cooking. You seem to be asking about finer cuisine, not regional dishes sold locally in every tourist restaurant.
Edit: I agree throughly with KGC just below. It's the small places where a whiz of a cook is in the kitchen and few guidebook writers have visited. We had several like that within 20 kilometers of my in-laws' village in Burgundy. However, be careful if the menu is too diversified with most of the choices in sauces and you don't smell anything coming from the kitchen. Chances are the main courses come frozen from restaurant wholesalers. We had a restaurant like that in my in-laws' village next to the local chateau.