This recipe is from Crazy Plates. I would just use mashed sweet taters as a topping, like a Shepherd's Pie due to our diet constraints.

PILED-HIGH VEGGIE POTPIE

FOR THE POTPIE:
1 cup EACH chopped onions and chopped red bell pepper
2 cloves garlic, minced
2 1/2 cups vegetable broth
2 cups peeled, cube potatoes
1 cup sliced carrots
1 1/2 teaspoons dried rosemary
1/2 teaspoon dried thyme
1/4 teaspoon EACH salt and black pepper
1 cup sliced asparagus pieces or sliced green beans
1/2 cup frozen green peas, thawed
3 Tablespoons flour
1/4 cup chopped, fresh parsley
FOR THE SWEET-POTATO BISCUIT CRUST:
1 1/2 cups flour
1 Tablespoon baking powder
1/2 teaspoon salt
3 Tablespoons butter or margarine, softened
3/4 cup cooked, mashed sweet potatoes
3/4 cup 1% milk, plus extra for brushing top of crust

Spray a large, non-stick saucepan with non-stick spray. Add onions, red pepper and garlic. Cook and stir over medium-high heat until vegetables begin to soften, about 4 minutes.

Add 2 cups broth, potatoes, carrots, rosemary, thyme, salt and pepper. Bring to a boil. Reduce heat to low. Cover and simmer for 12 minutes, until potatoes are almost tender.

Stir in asparagus and peas. Cook for 3 more minutes.

In a small bowl, mix 3 Tablespoons flour with remaining 1/2 cup vegetable broth until smooth. Add to vegetable mixture. Cook until bubbly and thickened.

Stir in parsley. Transfer to a 2 quart casserole dish that has been sprayed with non-stick spray. Set aside.

Preheat oven to 425 degrees F.

In a large bowl, combine flour, baking powder and salt. Cut in butter until mixture resembles coarse crumbs.

Whisk together sweet potatoes and milk, then add to flour mixture. Stir until a soft ball forms. Transfer dough to a lightly floured surface and roll or pat out to fit top of casserole. Place dough over vegetables. Brush with milk.

Bake for 20 minutes, until crust is puffed up and golden brown. Let cool for 5 minutes before serving.

Makes 6 servings.