Simpler Shepherd's Pie

I used to make shepherd's pie back when I was vegetarian, and I made a really good vegetarian version.  I used lentils which I thought was brilliant!  I still think it's brilliant so I still include them, but I no longer make the vegetarian version.  And I used to make it using about 5 different pots and pans, not to mention my mixer bowl.  I don't have time for all those pots and pans anymore!  I now make it much simpler, and I think it's probably just as good.  You can substitute any vegetable that you want.

And oh, yeah, this is probably more like the Hamburger Pie that I grew up with than shepherd's pie.  It doesn't have the traditional gravy, and instead uses tomatoes.  Which in my mother's version, was more of a cream of tomato soup (but not the nasty canned kind).  I just used tomatoes tonight, so that I would not have to dirty more pans.

1 pound ground beef
1 onion, chopped
1 clove of garlic, chopped
1/2 cup lentils (I like the French green ones)
1 28 ounce can of tomatoes, diced
4 carrots, sliced or diced
about 8 cups of trimmed, cut-up green beans
3-4 large potatoes
sour cream to taste
butter to taste
salt and pepper to taste
milk or buttermilk or half and half
about 1/2 cup of grated sharp cheddar cheese

Cook the ground beef in a large oven-proof skillet over medium-high heat, and while it's cooking add the onion, garlic and the lentils.  When the beef is browned, add the tomatoes.  Cook for 5-10 minutes, stirring occasionally.  Add the vegetables and cook for 5 minutes.  Lower the heat to medium-low and cover.  Cook for 10 minutes or until the lentils, carrots, and green beans are cooked through.  Salt and pepper this mixture.

Meanwhile, cook the potatoes in a pan with water.  When they are tender, mash.  You can mash them right in the pan if you have a masher, but I like to use my kitchen aid mixer.  Add sour cream, butter, salt and pepper, and whip, adding milk as needed.  It will really depend on the potatoes as to how much milk they will absorb.

Spread the mashed potatoes over the meat mixture, right in the pan if it is oven-proof.  Sprinkle cheese over the top and bake at 400 degrees until bubbly and the cheese is melted, about 30 minutes.  Serve immediately.