TheFork users who ate in Montigny-le-Bretonneux have said really good things about Auberge du Manet, La Ferme de Voisins and Bistro Birdie. Maybe you should give them a try!
Some of the more popular Seminar restaurants having a terrace in Montigny-le-Bretonneux according to TheFork users include:
La Fontaine, with a 9.2 rating
La Flambée - Montigny Btx, with a 9.3 rating
Choiseul, with a 8.7 rating