In a large bowl, cream together the shortening and sugar until light and fluffy. Stir in the eggs one at a time, beating well with each addition, then stir in the banana and vanilla.
Add in the flour, baking soda and salt. Beat into creamed mixture. Stir in oats, nuts and chocolate chips. Pour into prepared loaf pan.
Bake in preheated oven for 50 to 55 minutes, or until a toothpick inserted into the center of the loaf comes out clean. You might need to cover with foil for the last 10 minutes or so to keep it from getting too brown on the edges.