Turn the broiler on high. Place the bell peppers on a baking sheet and place under the broiler. Turn every few minutes until both peppers are completely black
Remove from the broiler and place in a bowl and cover with plastic wrap for 10 minutes.
Turn off the broiler and preheat the oven to 425.
Combine egg yolk, spinach, garlic, lemon juice, vinegar, cheese, and bread crumbs in a bowl. Set aside
Once the peppers are cool enough to touch, peel off blackened skin, it should come off easily. Dice the peppers and add them to the spinach mixture.
Butterfly the steak (or have the butcher do it!) and lay it out. Spread the spinach mixture on top leaving a one inch boarder around the edges.
Roll steak up and secure with kitchen twine.
Sprinkle Salt and Pepper over the steak roll.
Bake for 35 minutes.
Turn on the broiler again and bake for 10 minutes more, turning once. This browns up the meat beautifully.
Remove from the oven and let rest for 10 minutes, slice and serve.