Preheat oven to 425 F. In a bowl place butternut squash, olive oil, salt and pepper. Toss to combine. Spread on a baking sheet ans roast for 45 minutes, until tender and the edges are crisp.Toss a couple of times during baking.
For the steak:
Combine all ingredients for the marinade in a bowl and stir to combine. Place steak in a large zip lock bag and pour marinade on top. Seal to close. Let the meat marinate for at least 1 hour or overnight.
Preheat a gas grill to medium-high heat (450F). Clean and oil the grates. Grill steak for 10-12 minutes per side, until browned and fully cooked. Transfer to a cutting board and let it rest for 5 minutes, then cut into cubes.
For the crostini:
Prepare a baking sheet and spray with cooking spray. Arrange bread slices on the sheet. Drizzle with olive oil (or spray with cooking spray on top). Bake for 15 minutes at 300 F until golden.
To assemble the crostini: top each slice of bread with 1 tbsp chopped steak, 1 tbsp butternut squash and sprinkle some pomegranate seeds and feta cheese. Garnish with chopped parsley.