• Cook pasta according to package directions, reserving 1/2 cup of the cooking water. Drain and set aside.

While the pasta is cooking:

• Into a large deep skillet over medium-high heat, add the sliced sausage. Cook until browned on both sides, approximately 5 minutes. Remove the cooked sausage from the skillet and set aside.
• Into the same skillet over medium-high heat, add the olive oil. When the oil is hot, add the diced onion. Cook, stirring frequently, 2-3 minutes until onion is softened. Reduce heat to low.
• Add the pesto, sea salt, and ground black pepper. Stir to combine.

Putting it all together:

• To the pesto mixture, add the cooked pasta and reserved 1/2 cup pasta cooking water. Toss to coat.
• Add the shredded parmesan cheese and cooked sausage.
• Increase heat to medium then cover for about 2-3 minutes, to heat through.
• Adjust seasoning to taste.
• Serve hot.