To store leftover grinder sandwiches with pesto, wrap them tightly in plastic wrap or aluminum foil and place them in an airtight container. They can be kept in the refrigerator for up to 2 days. For best results, consider storing the ingredients separately, especially the lettuce and tomatoes, to prevent them from becoming soggy.

Absolutely! To create a vegetarian grinder sandwich with pesto, simply omit the meats and add extra vegetables like roasted red peppers, cucumbers, or grilled zucchini. You can also increase the amount of avocado for added creaminess and nutrition.

If you don't have provolone cheese on hand, you can substitute it with mozzarella, gouda, or even a sharp cheddar for a different flavor profile. Each of these cheeses will melt well and complement the pesto and other ingredients in the sandwich.

To make a gluten-free grinder sandwich with pesto, simply use gluten-free bread. There are many delicious gluten-free options available, such as almond flour bread or gluten-free whole grain bread, which will work well with the other ingredients in the sandwich.

A grinder sandwich with pesto pairs well with a variety of side dishes. Consider serving it with a light salad, such as a cucumber and tomato salad, or some crispy baked sweet potato fries. For a refreshing touch, you could also serve it with a side of pickles or a fruit salad.