Step 1Place a rack in the upper third of the oven and heat the oven to 325 degrees.
Step 2Heat the butter or oil in a large nonstick skillet over medium heat. When it's hot, add the onion, bell pepper, ham, salt and pepper to taste. Cook, stirring often, until the onion is soft, about 5 minutes. Stir in the flour. Set aside.
Step 3Whisk the eggs well in a large bowl. Whisk in the cream, stir in the Gruyere and Fontina cheeses and the vegetable mixture. Ladle into the cooled crust. Set the pan on a baking sheet.
Step 4Bake the quiche until it is puffed and golden, 55 to 60 minutes. Cool it at least 15 minutes before serving. Remove the ring; slide the quiche off the bottom and onto a large serving plate. This can also be served at room temperature.