Preheat oven to 350 degrees Fahrenheit (175 degrees C).

In a large bowl, combine the cooked chicken, lemon juice, cream of chicken soup, cream of mushroom soup, mixed vegetables, chicken broth, and softened margarine.

Mix all ingredients thoroughly.

Pour the mixture into a casserole dish.

On a lightly floured surface, roll out the thawed biscuits until flattened.

Piece the flattened biscuits together to cover the top of the casserole dish, creating a crust.

Place the casserole dish in the preheated oven.

Bake for 1 hour, or until the biscuit topping is golden brown and the filling is bubbly.

Let cool slightly before serving.