Preheat oven to 450°F.
In a saucepan, melt the butter and sauté the onion and red bell pepper until soft, about 5 minutes.
In a large mixing bowl, combine the breadcrumbs, thyme, parsley and cheese. Add the melted butter mixture and combine well.
Arrange the opened clams on a rimmed baking sheet. Place a slice of bacon on each clam, and top with the breadcrumb mixture.
Bake for 5-8 minutes, or until the tops of the clams are golden brown.
