Hearty Mushroom Parnsip Sauce

This is a modified recipe from Epicurious. I serve it over the Instant Pot Polenta.

I know this looks gross, sorry.

Mushroom Parsnip Sauce 

2 TBSP olive oil, divided

1 small onion (~3/4 cup), chopped

3 cloves garlic, finely minced (or run through garlic press)

1/2 tsp fresh thyme, chopped (or 3/4 tsp dried)

1 parsnip, peeled and chopped

12 oz mushrooms (any kind you like), roughly chopped 

1 TBSP miso paste

1-2 TBSP tomato paste

1/2-1 tsp cornstarch (use smallest amount first, add more if necessary to thicken)

Kosher salt

1/8 cup red wine vinegar+1/8 cup water, OR 1/4 cup red wine

1.5 cups water

1. Heat 1 TBSP oil in Dutch oven over MEDIUM heat, cook onion, garlic, thyme for 3 minutes.
2. Add parnsnip and cook until soft, about 5 minutes,
3. Add mushrooms and remaining1 TBPS oil and cook for 7 minutes, until well browned. 
4. Add miso, tomato paste, and 3/4 tsp salt, cook for 1 minute.
5. Add cornstarch, cook for 30 seconds.
6. Add red wine vinegar+water OR red wine to deglaze, scraping up all the brown bits on the bottom of the pot.
7. Add 1.5 cups water, stir until combined.
8. Cook for 10-12 minutes until water is absorbed and sauce is somewhat thickened.
9. Serve over Instant Pot Polenta. 

Notes

I typically just buy the presliced mushrooms for this dish. Chopping them smaller helps them brown better, but you don't have to.

Centro brand tomato paste (yellow can) is 100% the best out there you can literally eat it out of the can with a spoon. And I do.

Water is absolutely an ingredient and I don't understand why it is never listed in ingredient lists. Drives me crazy.

I don't drink, so when a recipe calls for wine I use half white/red/champagne/etc (whatever wine it calls for) vinegar and half water for the given measurement. Red wine vinegar in red spaghetti sauce is my special secret.