In a small bowl, combine the minced garlic, olive oil, lemon juice, salt, pepper, and chili flakes (if using). Set aside while you prepare the chicken and vegetables.
Place the vegetables, chicken and sausage in a large bowl or Ziploc bag, and add the olive oil mixture and toss to coat. (You can also do this in advance and let your chicken and vegetables marinate in your fridge/cooler for up to 24 hours.)
Divide the mixture evenly, placing the ingredients in the center of each of the four pieces of tinfoil.
To seal the packets, bring the two outer edges of each piece of tinfoil together and fold over until almost flat against the ingredients. Fold the two open ends of the packet over twice to close. It should look like a fancy little tinfoil present.
Place your campfire chicken packets, seal side up, in the coals of a campfire or on a covered grill for about 20 minutes (depending on how hot your fire is) or until the chicken is cooked through and the vegetables are tender. If you are making these indoors at home (still awesome), you can bake your packets in a 400 degree oven for 30 minutes.
When your packets are cooked, carefully open them (there will be steam, people), and sprinkle each packet with Parmesan cheese and freshly chopped basil. Classy campfire food at its finest! You’re so outdoorsy.