Heat a large cast-iron skillet or griddle pan over medium-high heat. Bring steaks to room temp and season with Kosher salt and black pepper.
For the veggies, heat a large braising skillet or pan with a lid over medium to medium–high heat with 3 turns of the pan olive oil. Add pancetta and stir to render its fat for 2-3 minutes. Add the onions and stir; partially cover pan and sweat 5 minutes.
Trim root end of celery and use a peeler to peel away very fibrous lower portions of the celery ribs then cut into 3 inch pieces on a bias. Peel and trim tops of carrots and parsnips, and cut into 1-inch slices on bias. Add to the pan with onions and pancetta, and stir to coat the celery in drippings and oil. Season with salt and pepper then add bay leaves and chicken stock. Reduce heat to medium-low and cover. Cook 15-20 minutes. Just before serving add lemon juice and parsley.
Add canola or olive oil to the steak pan and place steaks in skillet or on griddle. Cook 8-10 minutes, turning occasionally; remove to rest. Turn pan off, add butter and allow it to foam; add garlic, swirl then add hot sauce. Turn steaks in sauce or brush with sauce.
Top steaks with blue cheese crumbles and chives or scallions, and serve braised vegetables alongside.