Heat oil in a large saucepan over medium-high heat. Add onions and cook until soft, about 4 to 5 minutes. Add garlic and red pepper flakes and cook for 1 minute. Add remaining ingredients, reduce heat to medium-low and cook until thickened, about 35 to 40 minutes.
Heat grill to high. Season steaks on both sides with salt and pepper. Grill, on 1 side, until crusty and slightly charred, about 4 to 5 minutes. Turn steaks over, close the hood and continue grilling for 6 to 8 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 and top with the Cherry Pepper-Tomato salad.
Whisk together vinegar, garlic and salt and pepper in a medium bowl. Slowly whisk in the olive oil. Add the peppers, tomatoes and parsley and stir to combine. Adjust seasoning and let sit 30 minutes at room temperature before serving.
Recipe courtesy of Bobby Flay