Set a 6-qt Instant Pot® to the high saute setting. Add bacon and cook until brown and crispy, about 6-8 minutes. Transfer to a paper towel-lined plate, reserving excess fat in the Instant Pot.
Season chicken thighs with 1 teaspoon salt and 1/2 teaspoon pepper.
Working in batches, add chicken to the Instant Pot®, skin-side down, and sear both sides until golden brown, about 2-3 minutes per side; set aside. Drain excess fat, reserving 2 tablespoons in the Instant Pot®.
Add mushrooms and shallots, and cook, stirring occasionally, until mushrooms are tender and browned, about 5-7 minutes; season with salt and pepper, to taste.
Stir in garlic until fragrant, about 1 minute.
Whisk in flour and tomato paste until lightly browned, about 1 minute.
Stir in wine, scraping any browned bits from the bottom of the Instant Pot®. Stir in chicken stock, carrots and thyme.
Return chicken to the Instant Pot®. Select manual setting; adjust pressure to high, and set time for 15 minutes. When finished cooking, quick-release pressure according to manufacturer’s directions.
Set chicken and vegetables aside. Select high sauté setting; simmer until the sauce has reduced and slightly thickened, about 8-10 minutes; season with salt and pepper, to taste.
Serve chicken and vegetables with juices immediately, sprinkled with bacon and garnished with parsley, if desired.