3 parsnips, peeled and cut into 1/2 inch pieces
3 carrots, peeled and cut into 1/2 inch pieces
1 sweet potato, peeled and cut into 1/2 inch pieces
3 tablespoons butter
2 cups sliced mushrooms
1 cup chopped leeks
3 tablespoons all-purpose flour
2 cups vegetable broth
1/8 teaspoon dried thyme
salt and ground black pepper to taste
1/4 teaspoon hot pepper sauce
2 1/4 cups biscuit baking mix
3/4 cup milk