Pat beef dry with paper towel and sprinkle with paprika, all but 1 pinch salt, cayenne and black pepper. In a large heavy pot or Dutch oven, heat 1/2 tbsp oil on medium-high. Add half of beef and cook, undisturbed, for 2 to 3 minutes, until bottom is browned; flip beef and repeat on opposite side. Transfer to a large plate and repeat with remaining 1/2 tbsp oil and beef; set aside.Add onion to pot and cook until soft and lightly browned, about 6 minutes. Reduce heat to medium-low and add thyme, rosemary, tomato paste and garlic; mix well. Return beef and any accumulated juices to pot. Sprinkle with flour and cook for 1 minute, stirring constantly. Add 2 tbsp vinegar and simmer for 1 minute, until slightly reduced. Add broth and bay leaves, cover and increase heat to medium-high. Once mixture begins to simmer, immediately reduce heat to medium-low or low, adjusting as necessary to maintain a slow, steady simmer. (NOTE: You should see no more than a few bubbles gently rising to the surface at any given time.) Cover and cook for 1 hour and 15 minutes, stirring 2 to 3 times.Add carrots, cover and simmer for 30 minutes. Add potatoes, cover and simmer for 10 minutes. Add celery root, cover and simmer until vegetables and beef are tender, 20 to 30 minutes.Meanwhile, coat a large skillet with cooking spray and heat on medium-high. Add mushrooms, remaining 2 tbsp vinegar, remaining pinch salt and black pepper. Toss to combine and cook, stirring frequently, until mushrooms begin to soften and release liquid, 3 to 5 minutes. Reduce heat to medium-low and cook until mushrooms are tender and vinegar is almost completely reduced, about 3 minutes.To pot, add peas and return to a simmer; cook until just heated through, 1 to 2 minutes. Stir in mushrooms and remove from heat. Remove bay leaves and serve immediately.