Preheat oven to 250.
Remove a thin lengthwise slice from the top of the French bread. Discard slice (or nibble on it!). Scoop out inside of loaf, leaving about 1 inch of bread on all sides and bottom of loaf. Tear scooped-out bread into small pieces. Measure 1 cup evaporated milk. Add 1 cup bread pieces and let soak 10 minutes.
Mix chopped bell pepper and chopped onion with ground beef. Add milk-bread mixture and stir well.
Spoon mixture into hollowed-out loaf, making sure that the mixture extends to the ends of the inside of the loaf. Place on a cookie sheet and bake on middle oven rack for 1 and 1/2 hours. Remove and let stand briefly, then slice and serve. Bread and main dish all in one.