Wash and dry the lettuces, then tear the Romaine into not-too-small pieces. Leave the butter lettuce leaves whole if they’re on the smaller side. Arrange both lettuce leaves in individual salad bowls.
Make breadcrumbs. Tear the bread into small pieces, then add to the bowl of a food processor. Pulse into coarse breadcrumbs.
Make the pangrattato. Heat 3 Tbsp olive oil in a skillet over medium-low heat. Add 1 cup of breadcrumbs then cook, stirring often, until they begin to look golden brown and are crispy, about 5 minutes. Stir in 1 grated clove of garlic and 2 Tbsp pine nuts. Continue to toast, stirring often, until deep golden brown, being careful not to burn the pine nuts, a few minutes more. Remove from the heat, then immediately stir in 2 Tbsp finely grated Parmesan, 1 tsp chopped mint (or parsley), ¼ tsp kosher salt, and ¼ tsp black pepper. The residual heat melts the cheese slightly, helping it cling to the crumbs. Transfer to a bowl and let the pangrattato cool—it will crisp up even more as it rests.
Make the lemon vinaigrette. In a bowl (or jar), whisk together 4 Tbsp (60ml) lemon juice, 1 grated clove of garlic, 1 tsp Dijon mustard, 1 tsp honey, 1 tsp kosher salt, and ¼ tsp black pepper. Slowly drizzle in the extra virgin olive oil while whisking until emulsified (or simply pour into the jar, seal tightly, then shake until well mixed). Taste and adjust seasoning, then stir in chopped parsley if using.
Assemble. Drizzle just enough vinaigrette to lightly coat the leaves. Toss gently, then finish with a generous handful of pangrattato, a pinch of flaky sea salt, and extra Parmesan if desired. Serve immediately for maximum crunch.