In a blender or food processor, combine the egg yolks, Dijon mustard, lemon juice, garlic, Worcestershire sauce, olive oil, black pepper, and Parmesan cheese. Blend until smooth. Set aside.
Heat 1 tablespoon of olive oil on a griddle. Add the cubed sub rolls and toast for 3–5 minutes until golden and crisp.
On the same griddle or a separate pan, cook the chopped pancetta (or bacon) until crispy. Leave the rendered fat on the pan.
Add the toasted croutons back into the pan with the pancetta fat. Mix well to coat.
Stir in the garlic paste with the croutons and pancetta, tossing until evenly coated. Remove from heat and set aside.
Drizzle a little oil on the griddle and sprinkle with ½ teaspoon salt. Grill the halved romaine heads cut-side down for 2–3 minutes per side until lightly charred.
Place the grilled romaine on a serving platter. Top with the crouton and pancetta mixture. Drizzle generously with the dressing.