Vegetable Gravy

 
In a 12" cast iron skillet, saute:

2 tablespoons butter
1 onion, diced
2 stalks celery, diced
1 bell pepper, diced
Once caramelized, add
12 oz mushrooms, sliced
and sear until caramelized. 

Sprinkle dried or fresh thyme, salt and pepper over vegetables. 

Push vegetable to the outer rim of the skillet. Add 3 more tablespoons butter to the center, and once it melts, pour 1/2-3/4 cup spent leaven to the skillet. Stir into butter, then gradually into veggies. Make sure all flour is browned in butter. Pour 2-3 cups of chicken or vegetable broth (I've even used whey!), using a fish spatula to mash the clumps of leaven to break them up. Once the gravy begins to boil, it will thicken.

We love this over baked potatoes and steamed broccoli! I've also made a casserole with rice and broccoli by pouring this over the top in a 9x13.