Grinder Sandwich (TikTok Viral Salad Sandwich)

Name: Grinder Sandwich (TikTok Viral Salad Sandwich)
Prep time: 20 min
Total time: 20 min
Cuisine: American
Ingredients: 1/4 red onion (thinly sliced); 1/3 cup mayonnaise; 2 teaspoons red wine vinegar; 1/2 teaspoon Italian seasoning (I used Penzey's frozen pizza seasoning); 1 to 2 Tablespoons banana peppers (chopped with juice); 4 to 5 cloves minced garlic; dash crushed red pepper (optional); salt; pepper; 1/4 to 1/3 head iceberg lettuce (sliced); 2 to 3 sub rolls; sliced ham; salami; Munster cheese; 1 tomato (sliced); grated Parmesan cheese