vegetable shepherd's pie

1c diced carrots
2 stalks celery, diced
1 small onion, diced
1/2lb frozen peas, (don't thaw)
3/4-1c corn
1-2tsp olive oil
2Tbsp worchestershire
2-3 Tbsp tomato paste
2-3 Tbsp ketchup
salt and pepper
For mashed potatoes:
3-4 medium-sized potatoes
2 Tbsp butter
1/4c milk (I use skim)
sour cream (I usually use about 1/4c)
salt and pepper
3/4 c cheese of choice (cheddar, white cheddar, gruyere, parmesan, etc.)

Prepare mashed potatoes by washing and peeling the potatoes and halving them. Cover with water and bring to a boil. Cook until very tender and starting to fall apart. Drain and stir in butter and milk. Add salt, pepper, and sour cream to make a sturdy mashed potato (you don't want it watery or thin). While potatoes are still quite warm, stir in about 3/4c of your desired cheese and stir until well combined and cheese is mostly melted.

Meanwhile, in a large pan, saute carrot, celery, and onion in olive oil until cristp-tender (this took me about 5 minutes. You want it to have a little bite left since it will cook longer in the oven). Salt and pepper to taste. Stir in corn, tomato paste, and worchestershire sauce. Cook 2-5 minutes or till sauce thickens slightly. Stir in additional worchestershire or tomato paste as necessary. Stir in 1 Tbsp ketchup. Cook 1-2 minutes and taste. Season as necessary, then stir in peas. Pour into a 2qt casserole dish (I use my round one or my 11 x 7). Top with mashed potato mixture. Rough up the surface of the potatoes with a fork (I usually just make a design).

Bake at 400 for 10-12 minutes or till potatoes start to turn golden or you can't wait any longer.