Step 1
Preheat oven to 400 degrees F (200 degrees C). Line baking sheets with aluminum foil.
Step 2
Melt butter in a skillet over medium-high heat. Whisk flour into hot butter and cook whisking constantly until mixture is pale and flour taste cooks off about 1 minute. Pour milk into flour mixture and cook whisking constantly until mixture is hot and thickened 3 to 6 minutes. Add 2 ounces provolone cheese nutmeg cayenne pepper and salt; stir until cheese is completely melted. Remove from heat.
Step 3
Season steak all over with salt and ground black pepper.
Step 4
Heat 1 tablespoon olive oil in skillet over medium-high heat. Cook steak in hot oil turning occasionally until meat is slightly firm and pink on the inside 5 to 7 minutes. Transfer meat to a plate.
Step 5
Return skillet to heat and pour water into the skillet; bring to a boil while scraping the browned bits of food off of the bottom of the pan with a wooden spoon. Pour liquid from the skillet over steak. Cool steak to room temperature; dice meat and place meat and accumulated juices from the plate into a large bowl.
Step 6
Heat 1 tablespoon oil in a skillet over medium-high heat; saute onion and peppers in hot oil until softened and slightly translucent about 5 minutes.
Step 7
Stir peppers and onions mixture into diced meat; season with salt and pepper.
Step 8
Spread bread slices out on prepared baking sheets and drizzle remaining olive oil over the top. Turn slices over so that the oiled-side is facing down. Spread a thick layer of cheese mixture onto each slice. Spoon meat mixture over cheese. Sprinkle provolone cheese over the top of each slice.
Step 9
Bake in the preheated oven until browned and cheese is melted 12 to 15 minutes.