Put a large pot of water on the stove to bring to a boil for pasta.
Preheat broiler to high with rack on top shelf.
Preheat medium skillet over medium-high heat. Add chopped bacon and cook until crisp.
Salt water for pasta and add spaghetti to the pot. Cook to al dente, with a bite to it.
Season the steaks with salt and pepper on both sides and arrange on slotted broiler pan.
Remove bacon to paper towel lined plate with a slotted spoon and drain off most of the fat, return pan to heat and reduce heat to medium. Add extra-virgin olive oil, 2 turns of the pan and 1 tablespoon butter. When butter melts into extra-virgin olive oil, add in 2 cloves garlic and the shallots, saute for 3 minutes.
Arrange steaks on the broiler pan. Place under broiler - leave door to oven cracked ajar to limit flare ups and smoke. Cook 4 minutes on each side for medium rare, up to 5 to 6 minutes on each side for medium well doneness.
To the garlic and shallots, add in flour and cook a minute more. Whisk in stock, bring to a bubble, about 30 seconds then stir in the cream. When cream comes to a bubble, add in blue cheese and sage and a few grinds of black pepper. Stir until cheese melts. Reduce heat to lowest setting.
Soften 4 tablespoons butter in microwave on high for 15 seconds. Mix in chives and 2 cloves minced garlic and reserve.
Remove steaks from oven and let rest 5 minutes. Place 1/4 of the chive and garlic butter mixture on each steak to melt down over the meat as they rest.
Drain pasta and toss with sauce to coat and combine evenly. Taste to adjust seasoning.
Serve steaks with pasta alongside. Scatter the arugula and bacon bits across the top of the pasta.