What's for Dinner? Shepherd's Pie with Cauliflower

This recipe caught our (okay, Matt's) attention when we were at my parents over the holiday. I thought it sounded more edible with the cauliflower added.

1 lb lean ground beef
1 onion, minced
1 handful baby carrots, sliced
1 large can mushrooms, drained and liquid reserved
1 t dried thyme, rubbed
2 T flour
1/2 cup beef broth plus reserved mushroom liquid
salt and black pepper to taste, divided
1 cup frozen peas
4 potatoes, peeled and quartered
1/2 head cauliflower, broken into florets
2/3 cup buttermilk
2 T butter

In a large frying pan or skillet over medium heat, cook the meat and veggies, til beef is cooked and veggies soften, about 10 minutes. Drain. Stir in thyme and cook another minute or so.

Add the flour and cook til mixture thickens. Stir in broth and salt and pepper; cover and simmer about 10 minutes. Stir in the peas and cook another 5 minutes or so.

Meanwhile, boil potatoes in salted water for about 10 minutes. Add cauliflower and cook another 10 minutes or til the potatoes and cauliflower are very tender. Mash potato mixture with buttermilk, butter and salt and pepper.

Preheat oven to 400°. Spray a 9x11" baking pan with cooking spray.

Pour beef mixture into prepared pan. With a rubber spatula, spread mashed potato mixture on top of meat and bake til hot and bubbling, about 30 minutes.

Matt loves this stuff.

Adapted from Ellie Krieger