Preheat oven to 400 degrees. Line a large sheet pan with parchment paper. Add the potatoes to the sheet pan and mix together the italian seasoning and salt in a small bowl. Toss the potatoes with half of the olive oil and season with a liberal amount of the seasoning mixture, (the potatoes need the most seasoning).
Turn the potatoes face down and move to 1/2 of the sheet pan. To the other half, toss the carrots and red onion with the remaining olive oil and a sprinkling of the seasoning, leaving a final bit of the seasoning for sausage, green beans and pepper.
Roast potatoes, carrots and onions for 15 minutes while you sear the sausages. To a large saute pan over medium-high heat, add a drizzle of olive oil and the sausages with a sprinkling of seasoning. Brown sausages on each side for 2-3 minutes until all sides are golden brown. Set aside.
When potatoes, onions and carrots have reached 15 minutes, remove the pan from the oven. Leave the potatoes alone but push the onions and carrots to one quadrant. To the remaining quadrant, add the green beans and red bell pepper, sprinkling with seasonings and a final drizzle of olive oil. Return to the oven for an additional 15 minutes.
When veggies have roasted, remove pan from over and add the minced garlic nestled in and sausages atop. Return to oven for a final 5 minutes to roast. Remove from oven and toss everything together with lemon zest and fresh parsley. Serve and enjoy!