|For pear topping|
|Vegetable oil||2 Teaspoon (preferably canola oil)|
|Packed light brown sugar||1⁄3 Cup (5.33 tbs)|
|Coarsely chopped walnuts||1 Tablespoon|
|Firm ripe pears||2 , peeled, cored and cut in 1/4-inch-thick slices (such as Anjou or Bosc)|
|All purpose white flour||3⁄4 Cup (12 tbs) (plus 2 Tbsp)|
|Corn meal||6 Tablespoon (yellow or white, preferably stone-ground)|
|Baking powder||1 Teaspoon|
|Baking soda||1 Teaspoon|
|Ground cinnamon||3⁄4 Teaspoon|
|Cold unsalted butter||1 Tablespoon, cut into pieces|
|Vegetable oil||1 Tablespoon (preferably canola oil)|
|Plain non fat yogurt||1⁄3 Cup (5.33 tbs)|
To make pear topping: Place rack in the lower third of the oven; preheat to 425 degrees F.
Heat oil in a 7- or 8-inch nonstick, ovenproof skillet over medium heat.
Add brown sugar and cook, stirring, for 1 to 2 minutes, or until the sugar has partially melted.
Remove from heat, scatter walnuts in skillet.
Arrange pears in the pan in a circular pattern.
To make biscuit and bake tatin: In a medium-sized mixing bowl, stir together flour, cornmeal, sugar, baking powder, baking soda, cinnamon and salt.
Using a pastry cutter or two knives, cut in butter and oil until the mixture resembles coarse meal.
In a small bowl, combine yogurt and 1/3 cup cold water.
Make a well in the center of the dry ingredients, pour in yogurt mixture and with a fork, stir until just combined.
Drop spoonfuls of the dough evenly over the pears.
Place the skillet on a baking sheet and bake for 20 to 25 minutes, or until a toothpick inserted into the center comes out clean.
Cool on a rack for 2 to 3 minutes, run a knife around the edge of the skillet and invert the cake onto a plate.