Preheat the oven to 350 degrees F. Spray 4 (7-ounce) souffle dishes with nonstick spray.
Heat the canola oil over medium-high heat in a medium saucepan. Add the flour whisking constantly for about 3 minutes, do not brown. Whisk in the warm milk until thickened, about 3 more minutes. Turn off heat and let cool slightly. Whisk in the egg yolks, then the cheese, ham (reserve 1/3 cup of the ham for the Round 2 recipe Savory Bread Pudding) and mustard. Let sit and cool slightly while beating the egg whites.
In another bowl with an electric mixer, beat the egg whites until soft peaks. Stir 1/4 of the whites into the ham and cheese base mixture to lighten, then fold in the rest of the whites. Fill each ramekin 3/4 of the way (reserve remaining souffle batter for the Round 2 recipe Savory Bread Pudding). Bake until puffed up and lightly browned on top. 15 to 20 minutes. Remove from the oven and serve.