Position an oven rack on the highest level in the oven. Preheat the broiler on high.
Arrange the peppers on a sheet pan in a single layer. Do the same with the onions and cherry tomatoes. This will create a bed of vegetables for the steaks to sit on.
Lay the steaks directly on the vegetables with an inch or two between the steaks so they aren't touching. Season the top of each steak with 1 teaspoon Montreal steak seasoning. Drizzle the top of each steak with 1 tablespoon olive oil. Top each steak with 1 tablespoon butter.
Broil until the tops of the steaks are nicely browned, about 5 minutes. Remove the pan from the oven and use a set of tongs to flip the steaks over. Sprinkle the other side of each steak with 1 teaspoon Montreal steak seasoning. Drizzle each steak with 1 tablespoon olive oil and top each with 1 tablespoon butter. Slide the pan back into the oven and broil the other side for 3 minutes.
Plate each steak with half of the veggies from the pan. Serve with a chunk of crusty French bread.