Preheat the oven to 375°F (190°C or 180°C for fan ovens).
Prepare the vegetables. Set aside.
Brush a large baking sheet (sheet pan) with a skim of olive oil and put the sausages in the oven to brown up a bit.
Cook for ten minutes, turning the sausages once or twice.
When the sausages have browned up a little, add all the vegetables to the pan.
Sprinkle with the pepper, basil, oregano and paprika.
Drizzle the remaining olive oil over the top, and toss everything together.
Return the pan to the oven.
Bake for 25 minutes, stirring the sausages and vegetables around once, until the vegetables have softened and are beginning to take on some colour.
Remove the sheet pan from the oven and sprinkle the lentils over top.
Drizzle the whole lot with the vinegar and toss to coat.
Return the pan to the oven for 5 minutes. The sausages should have reached an internal temperature of at least 165°F (74°C).
Serve in warmed bowls. Each person should have 2 sausages and a quarter of the vegetable mixture.
Garnish with flat leaf parsley.