Set a large dutch oven or heavy bottomed pot over medium heat. Add the pancetta and cook until crisp and then remove from the pan.

Add the butter and olive oil to the pan. Toss the stew meat with the flour and add in a single layer to the pot. Season with salt and pepper. Don't overcrowd the pan or the meat will steam instead of brown. Do this in two batches if necessary.

Once the meat is well browned, remove from the pan and add the onion, garlic, salt and pepper. Add additional oil if needed and adjust the temperature so the browned bits on the bottom of the pan do not burn.

Saute the onion and garlic until translucent and then stir in the tomato paste, anchovy paste and brown sugar.

Slowly add the wine, scraping all the brown bits from the bottom of the pan. Add the stock, soy sauce, worcestershire sauce, chocolate, thyme sprigs, half the parsley, and return the meat and pancetta to the pan. Season with salt and pepper.

Bring to a boil, then reduce to a simmer. Cover and reduce the heat to very low. Simmer for an hour, stirring occasionally.

Add the carrots and simmer, covered, for another hour.

In a separate nonstick saute pan, heat 1 Tbsp olive oil over medium high heat. Add the mushrooms and saute until browned. Reserve.

Remove the lid from the dutch oven and add the sautéed mushrooms and remaining parsley. Remove the thyme sprigs or stems and discard. Increase the heat to med/low and simmer uncovered until the beef is super tender, about another 20-30 mins.

Serve over rustic mashed potatoes if desired.