Place meatballs in a slow cooker and heat on low for 4-6 hours.

In a large skillet over medium-high heat, heat 1 tablespoon olive oil and saute bell peppers and onion slices until tender-crisp. Place on a plate or in a bowl with a fork or small tongs for serving.

Heat sauces according to package labeling until they are hot. Place in serving bowls with spoons or small ladles.

Place shredded and sliced cheeses each in their own bowl or plate.

Place hoagie rolls in a basket, large bowl, or stacked on a large plate or platter.

For convenience in assembling a meatball sub, place ingredients and toppings on a buffet table or countertop in the expected order they will be used.

Serve with potato chips and dip, veggie tray, or a salad.