Generously season meat with salt and pepper; set aside.
In a large skillet over medium-high, heat oil. Place meat, seasoned side down, and then season the top with salt and pepper. Quickly sear the beef, about 2 minutes per side. Transfer to a plate and set aside
Reduce heat to medium and add onions; sauté for 2 minutes. Add red and yellow peppers; sauté for 3 minutes. Add garlic and sauté for only 1 minute.
Pour in wine, increase the heat back to medium-high and cook until almost evaporated, about 3 minutes.
Add tomatoes, sugar and ½ tbsp. Italian seasoning, red pepper flakes, salt and pepper. Mix well and bring to a simmer; reduce to medium.
Pour in beef broth, capers and the remaining ½ tbsp. Italian seasoning; stir well.
Return the meat to the skillet, including any accumulated juices, and top about ¼ cup of cheese per piece; spoon sauce over.
Cover and cook until the meat warms up and the cheese is melted, about 5 minutes.
Served as is, on mashed potatoes, or over spaghetti, and garnish with basil leaves.