1. Remove root and green tops from leeks.  Slice in half lengthwise and rinse well under running water. Slice crosswise into ¼-inch slices.

2. Scrub potatoes well; cut into small cubes.

3. Melt margarine or butter in a 2-quart saucepan over medium heat.

4.  Add garlic and leeks. Cook until softened.

5. Add potatoes and enough broth to cover.  Cover pan and simmer until potatoes are soft.  Mash with a potato masher or fork until potatoes are fairly smooth. 

6. Add remaining broth, milk and pepper.  Simmer for about 5 minutes.