Preheat the oven to 375 degrees and line a baking sheet with parchment paper.
In a mixing bowl, combine the ground Italian sausage, breadcrumbs, egg, Parmesan cheese, half the chopped roasted red peppers, and oregano. Mix until evenly blended.
Divide the mixture into four equal portions and shape each into a small loaf. Place the loaves on the prepared baking sheet.
Spoon marinara sauce over each loaf and scatter the remaining roasted red peppers on top.
Bake for 25 to 30 minutes until the internal temperature reaches 160 degrees.
While the meatloaves bake, warm the prepared polenta in a saucepan over medium heat, stirring until smooth.
Spoon polenta onto plates, top each with a meatloaf, and finish with fresh basil leaves.