This is an Alsatian onion pie, sort of like a quiche. It's fine hot as an entree, but it's pleasant as a cold leftover also. Here's what you do.
1. Make the pastry, put in the pie shell, and set it aside (see recipe for Food Processor Tart/Pie Pastry).
2. Preheat oven to 375º
3. Slice the onions. You can do this by hand or in a food processor. They won't end up as slices, but as various sized rings and slivers. That's fine.
4. Melt the butter and saute the onions on the range, medium heat, until they are golden brown. You may end up using more butter than I've specified, but that's fine. Take them off the heat and put them in a mixing bowl.
5. Put the eggs and cream in a small mixing bowl and beat them up, using a whisk for example.
6. Now add the eggs/cream to the onions. Add salt, pepper and maybe a little sugar.
7. Now, pour the mixture into the pie shell.
8. At this point you have some options. You might want to add 6 ounces of Candida bacon to the top. I like it, but you can skip it.
9. It takes a fair amount of time to bake, and it depends on how watery it is. Use your judgment. A good first try is to put it in for 20 minutes, take it out and add a handful of grated Gruyere cheese to the top, and then put it back in for 10 or 15 minutes.
10. Serve hot. I typically have this as a main course with a salad. It's also pretty good, as I said, cold.