Sweet Onion Tart or Pie

recipe for 1 pastry pie crust for 9-inch pie (or use a refrigerated ready to bake crust)
2 tablespoons butter
2 1/2 pounds sweet onion, sliced (about 7 to 8 cups sliced)
1 large red bell pepper, seeded and chopped
3/4 teaspoon dried leaf thyme, crumbled
1/8 teaspoon ground black pepper

Roll out dough to a 12-inch circle. Press crust into a 10-inch tart pan or 9-inch pie plate. If a pie plate is used, crimp edges. In a large skillet over medium low heat, melt the butter. Add onions, red bell pepper, salt, thyme, and black pepper.

Cook, stirring, until onions are soft, about 15 minutes.

Place onion mixture in prepared pie crust. Bake at 375° for 40 minutes, until pie crust and the onions are golden, about 40 to 45 minutes. Serves 6.