Lentil Shepherd's Pie

Okay, so first of all, I tried using my immersion blender to make these mashed potatoes nice and smooth.  It was pretty smooth, but smooth in the sense of being the consistency of thick, pasty glue, which was a little off-putting.  If I were to do it again, I would just mash them by hand...  The good news is that after cooking this up, even though it still looked like glue, it didn't taste like it. 

Step 1:
4 large potatoes, quartered, cooked, and mashed with:
1 c. milk
salt and pepper

Step 2:
Saute the following in olive oil until they are soft:
1 large onion, diced
3 cloves garlic, minced
2 large carrots, chopped
about 1/2 lb. mushrooms, chopped
Then, mix in:
3 c. cooked peas

Step 3:
Cook together until tender:
1 1/2 c. lentils
3 c. water

Step 4:
Mix together the cooked vegetables, cooked lentils, and:
1 c. broth
1/2 c. tomato paste
Cook a little longer until most of the liquid is gone.  Pour the mixture into a 9x13" pan and spread the mashed potatoes on top.  Bake at 350F for 20-30 minutes.

There, that looks way nicer than those gross-looking mashed potatoes at the beginning: