Preheat your oven to 320°F (160°C).

In a large casserole dish or Dutch oven, heat olive oil over medium-high heat. Add the cubed chuck steak and sear until browned, about 5–7 minutes. Remove and set aside.

In the same casserole, add diced pancetta and cook over medium heat until crispy, about 4–5 minutes. Return beef to the bowl.

In the residual fat, add chopped onion, celery, and carrots. Season with salt and pepper. Sauté for 8–10 minutes until softened.

Stir in crimini mushrooms and minced garlic; cook for 2–3 minutes until fragrant.

Add red wine, balsamic vinegar, and tomato paste. Stir in beef broth and bring to a gentle simmer.

Combine the seared beef and crispy pancetta with the vegetables. Add bay leaf and rosemary, then cover and transfer to the oven. Bake for about 90 minutes.

If thickening is needed, mix cornstarch with cold water and stir into the stew during the last 15 minutes of baking.

Remove from oven, taste and adjust seasoning. Discard bay leaf and rosemary before serving over creamy polenta, mashed potatoes, or pasta.