Tear out 8 pieces of tin foil (about 12 inches each) and lay two pieces on top of one another so that you have four packets ready to be filled.
Place the potatoes, peppers and garlic in a large bowl and toss well with olive oil, oregano, salt and chili flakes. Divide mixture evenly and place in the center of each packet.
Top potatoes and peppers with one sausage each then begin creating grill packets.
Bring the two wide ends of the foil together and fold to seal. Gently fold in the smaller ends of the packet and continue to fold until tightly secured. Leave a bit of room in the packet for steam to form.
Grill for 9-11 minutes, turning once. The goal is caramelization as the sausage is already fully cooked.