Heat oil in a medium saucepan on side burners or grates of the grill. Add onion and garlic and cook until soft. Add red pepper flakes and cook for 1 minute. Add remaining ingredients, season with salt and pepper and cook until sauce has thickened, about 25 to 30 minutes.
Season steaks on both sides with salt and pepper. Grill until golden brown, about 4 to 5 minutes. Turn over and continue grilling for 4 to 5 minutes for medium-rare doneness. Baste with the sauce during the last few minutes. Remove from the grill and brush with more of the sauce. Let meat rest for 5 minutes then slice into 1/4-inch thick slices.
Cherry Peppers in Vinaigrette:
Preheat a grill. Preheat the oven to 400 degrees F. Toss the cherry peppers with 2 tablespoons of the olive oil in a bowl. Season with salt and pepper. Spread the peppers on a sheet pan and roast for 15 to 20 minutes, or until the skin is blistered. Set aside to cool slightly. Remove the stems and seeds from the cherry peppers and roughly chop.
Drizzle the red and yellow peppers with 2 tablespoons of the olive oil and season with salt and pepper. Place on the grill and cook until the skin is starting to blacken and blister. Remove from the grill and set aside to cool for 15 minutes. Roughly chop the peppers.
In a bowl, combine the cherry peppers, red and yellow tomatoes, parsley, and Basil Vinaigrette. Season, to taste, with salt and pepper. Serve.
Combine all ingredients and blend until smooth. Adjust seasoning with salt and pepper, to taste.