Cook the pasta according to the package directions. Drain and toss with butter and parmesan cheese while completing steps 2-5.
Slice kielbasa into small round pieces. In a large pan, brown kielbasa rounds in 1 tablespoon of extra virgin olive oil over medium heat for about 5 minutes, flipping once halfway through.
Thinly slice the peppers and garlic and dice the onion. Add to the pan with the browned kielbasa and cook for 5 minutes, until onions and peppers soften. Stir frequently.
Add the can of diced tomatoes, it's juices and Italian seasoning. Cover, turn heat to medium-low and simmer for 10 minutes. Season with salt and pepper to taste.
Serve the kielbasa mix over the buttered pasta, with additional Parmesan if desired.
Notes
Storing: kielbasa and pepper pasta keeps in the fridge for up to 5 days in a covered container.