1.
Preheat oven to 350 degrees F.
2.
Place bottoms of the rolls in a 9×13 baking dish; spread with half of the marinara sauce. Top with artichoke hearts, bell pepper, pepperoni, olives, and shredded cheese. Spread the remaining marinara sauce on the cut side of each roll top; place on top of each slider.
3.
Whisk together the grated Parmesan, olive oil, vinegar, butter, garlic, oregano, and red pepper flakes. Drizzle over the sliders.
4.
Cover baking dish with aluminum foil; bake for 30 minutes until cheese is melted and sliders are warmed through.