Preheat the oven to 350°F (175°C). Grease a 10" pie pan with butter, oil, or nonstick spray.

Grate the 1/2 pound cheddar and 1/2 pound Monterey Jack. Evenly sprinkle the shredded cheeses into the greased pie pan, pressing some up the sides so the cheese layer fills the pan to about half full.

In a large bowl, crack the 6 large eggs and whisk until blended.

Add the 1/3 cup all-purpose flour to the eggs and whisk until the flour is fully incorporated and there are no dry lumps.

Gradually whisk in the 1 2/3 cups half and half until the custard is smooth and uniform.

Pour the egg–flour–half and half mixture evenly over the shredded cheese in the pie pan. Pour slowly so the custard soaks down into the cheese.

Dollop the 1/3 cup salsa and the 4 ounce candiced green chiles evenly over the top of the quiche (distribute in several small spoonfuls so they are spread across the surface).

Bake in the preheated 350°F oven for 40–50 minutes, until the quiche is set: the center should not jiggle noticeably and a toothpick inserted into the center should come out clean.

Remove the quiche from the oven and cool on a wire rack for at least 10–15 minutes before slicing and serving to allow it to finish setting.