Blueberry Peach Cobbler w/Lemon Cornmeal Biscuit Topping

Jim's favorite, or just-about favorite, dessert is a cobbler.  Particularly peach.  Well, I had some leftover blueberries that I wanted to use up.  I've made a similar dessert (a Paula Deen recipe) in a crockpot.  I saw this recipe in a Cook's Illustrated magazine and just happened to have everything on hand, so decided to go with this one.  You can't go wrong.

BLUEBERRY PEACH COBBLER W/LEMON CORNMEAL BISCUIT TOPPING (Serves 6)

Filling:
2# peaches
1 cup fresh blueberries (about 5 oz)
1 tsp cornstarch
1 Tbsp juice from 1 lemon
pinch of salt

Biscuit Topping:
1 cup (5 oz) less 2 TBSP AP flour
2 Tbsp cornmeal
3 Tbsp plus 1 tsp sugar
1/4 tsp baking powder
1/4 tsp salt
5 Tbsp cold unsalted butter, cut into 1/4" cubes
1/2 cup plain whole milk yogurt (I couldn't find whole milk, I had to use fat-free)
1/2 tsp grated lemon zest

Adjust oven rack to lower-middle position and heat oven to 425.

FOR THE FILLING:
Peel peaches then halve and pit each.  Using small spoon, scoop out and discard dark flesh from pit area.  Cut each half into 4 wedges.  Gently toss peaches and sugar together in large bowl; let stand for 30 minutes, tossing several times.  Drain peaches in colander set over large bowl.  Whisk 1/4 cup of drained juice (discard extra), cornstarch, lemon juice, and salt together in a small bowl.  Toss peach juice mixture with peach slices and blueberries  and transfer to an 8" glass baking dish.  Bake until peaches begin to bubble, about 10 minutes.

FOR THE TOPPING:
While peaches are baking, in food processor, pulse flour, 3 Tbsp sugar, baking powder, baking soda, lemon zest, and salt to combine.  Scatter butter over and pulse until mixture resembles coarse meal, about ten 1-second pulses.  Transfer to medium bowl; add yogurt and toss with rubber spatula until cohesive dough is formed (don't overmix dough or biscuits will be tough).  Break dough into 6 (I made 9) evenly sized (I used a small biscuit cutter) but roughly shaped mounds and set aside.

TO ASSEMBLE AND BAKE:
 After peaches have baked 10 minutes, remove peaches from oven and place dough mounds on top, spacing them at least 1/2" apart (they should not touch).  Sprinkle each mound with portion of remaining 1 tsp sugar.  Bake until topping to golden brown and fruit is bubbling, 16-18 minutes.  Cool cobbler on wire racks until warm, about 20 minutes.  Serve.