Preheat and prep: Heat your oven to 425°F (220°C). Line a large sheet pan with parchment for easy cleanup.
Chop everything evenly: Slice the sausage and chop the vegetables into similar, bite-size pieces so they roast at the same rate.
Season: In a large bowl, toss the veggies with the oil, smoked paprika, garlic powder, onion powder, oregano, thyme, red pepper flakes (if using), 1 teaspoon salt, and 1/2 teaspoon black pepper.
Spread on the pan: Arrange the seasoned veggies in a single layer on the sheet pan.
Nestle the sausage slices on top and around the veggies so they can brown.
Roast: Cook for 15 minutes, then stir and flip pieces for even color. Roast another 10–15 minutes, until the veggies are tender with caramelized edges and the sausage is browned.
Finish: Taste and adjust salt and pepper. Squeeze a little fresh lemon over everything and sprinkle with chopped parsley for brightness.
Portion for meal prep: Divide into 4 meal-prep containers.
Let cool slightly before sealing.