3 tbsp. Crisco
1 sm. onion, chopped
1 1/2 tbsp. flour
1 1/2 c. milk
1 can cream of mushroom soup
1 can tuna
1 tbsp. lemon juice
Salt and pepper to taste
Bisquick biscuits

Brown onion in Crisco; add flour and blend. Add milk and stir until thickened. Add soup and tuna, juice and seasonings. Put into greased casserole. Top with Bisquick biscuits. Add grated cheese to biscuits if desired. Bake 400 degrees until biscuits are browned.