Leek Quiche

large leeks, about 1 1/2 to 1 3/4 pounds, white and light green part only

extra virgin olive oil or 1 tablespoon each olive oil and butter

Salt

garlic clove, minced (optional)

egg yolks

whole egg

Mediterranean pie crust (see recipe) or whole wheat yeasted olive oil crust

Freshly ground pepper

milk (2% or regular)

Gruyère, grated (3/4 cup tightly packed)