Flank Steak on Texas Toast with Chimichurri

INGREDIENTS

• 1/4 teaspoon crushed red pepper flakes
• 2 tablespoons Chimichurri to mix with mayonnaise
• 2 cloves garlic, minced (you can add to parsley and arugula in food processor)
• 1 1 1/2 to 2-pound flank steak
• 1/2 cup + 2 tablespoons olive oil
• 1/4 cup mayonnaise
• 1 cup flat leaf parsley cleaned and large stems removed, finely chopped (by hand or use food processor)
• 1/4 teaspoon dried oregano
• 1 beefsteak or heirloom tomato, sliced
• salt and pepper to taste
• 1/2 cup baby arugula, finely chopped (by hand or use food processor)
• 2 tablespoons red wine vinegar
• 1 brioche pullman loaf or if you prefer a white pullman loaf
• Soft butter for bread
• salt before you sear and pepper after