Heat olive oil in a large Dutch oven over medium heat.
Add the diced pepper, diced onion, salt, oregano, paprika, and black pepper to the pot and stir to coat with oil. Let cook until veggies soften, stirring regularly, 7-10 minutes.
Stir tomato paste into the veggies and let cook another minute.
Add the ground beef to the Dutch oven and cook until browned, about 5 minutes.
Stir the flour into the browned beef and cook for 2 minutes, stirring occasionally.
Add the milk, crushed tomatoes and their juice, and broth to the Dutch oven. Stir ingredients together and bring mixture to a boil.
Add the uncooked elbow pasta to the Dutch oven and stir to combine, making sure all pasta is submerged in the liquid. Let the mixture come to a boil again, then lower the heat to maintain a vigorous simmer. Cook the pasta in the mixture until al dente, stirring regularly, about 20 minutes.
Add 2 cups of grated cheese into the Dutch oven and stir to combine. Sprinkle the remaining 1 cup of cheese on top, along with more paprika and oregano if desired, then bake at 400F for 10-15 minutes until bubbly. Let cool slightly before serving.