Chicken Pot Pie Crumble

I thought this was really good but Matt gave it just a good rating. It's like having pie crust all throughout instead of just on the top and bottom.
Chicken Pot Pie Crumble
http://www.favfamilyrecipes.com/2011/01/chicken-pot-pie-crumble.html
1 1/2 Lbs chicken
3 cups chicken broth
2 tablespoons vegetable oil
1 onion , chopped fine (about 1 cup)
3-4 carrots, peeled and sliced (about 1 cup)
1/2 c. celery, chopped fine
salt and pepper (to taste)
4 tablespoons (1/2 stick) unsalted butter
1/2 c. flour
1 c. milk
3/4 c. frozen peas

Crumble Topping:
2 c. flour
2 tsp baking powder
3/4 tsp salt
1/2 tsp pepper
1/8 tsp cayenne pepper
6 Tbsp unsalted butter , cut into 1/2-inch cubes and chilled
3/4 c. Parmesan cheese
1 c. heavy cream

FOR THE CHICKEN: Bring chicken and broth to simmer in covered Dutch oven over medium heat (If you don't have a dutch oven, just use a stock pot). Cook until chicken is just done (8 to 12 minutes). Transfer cooked chicken to large bowl. Pour broth through fine-mesh strainer into liquid measuring cup and reserve. Do not wash Dutch oven.

FOR THE TOPPING: Combine flour, baking powder, salt, pepper, and cayenne in large bowl. Sprinkle butter pieces over top of flour. Using fingers, rub butter into flour mixture until it resembles coarse cornmeal. Stir in Parmesan. Add cream and stir until just combined. Crumble mixture into irregularly shaped pieces onto a baking sheet. Bake at 450-degrees until fragrant and starting to brown (10-13 minutes). Set aside.

FOR THE FILLING: Heat 1 tablespoon oil in now-empty Dutch oven over medium heat. Add onion, carrots, celery, salt and pepper. Cover and cook, stirring occasionally, until just tender (about 5 minutes). While vegetables are cooking, shred chicken into small bite-size pieces. Transfer cooked vegetables to bowl with chicken; set aside.

Heat butter in empty Dutch oven over medium heat. When foaming subsides, stir in flour and cook 1 minute. Slowly whisk in reserved chicken broth and milk. Bring to simmer and stir until sauce thickens, about 1 minute. Add salt and pepper to taste. Remove from heat and stir chicken-vegetable mixture and peas into sauce.

Pour mixture into 9x13 pan (or if you have small individual-sized oven-safe dishes, you can use those-- see picture above). Scatter crumble topping evenly over filling. Bake at 400-degrees until filling is bubbling and topping is well browned (about 12-15 minutes). Serve hot and enjoy!