Cook spaghetti according to dirctions, drain and set aside.
In saute pan, cook bacon until crisp. Lift out cooked bacon, drain on paper towels. Remove all but 2 TBS of bacon fat from the pan.
Season beef tips with salt and pepper, then add to hot skillet and sear beef until all sides are golden. Add onion and lightly saute. Add garlic and cook for 30 seconds. Add mushrooms and lightly saute. Add cooked bacon and tomatoes.
Deglaze pan with beer, let cook down by half. add butter, swirl in to make sauce.
Stir in cooked spaghetti, warm through. Stir in parmesan cheese and season with salt and pepper.
Serve in 2 pasta bowls, garnished with fresh basil and parmesan cheese.