Bring meat to room temperature for about an hour before grilling. Sprinkle chicken, lamb and filets with salt and pepper, rubbing them into the meat. Cut lemons in half.
Preheat barbecue to 500°F. Turn off the heat source on one side of the barbecue, and use that side to grill each type of meat to desired doneness. Begin by grilling the sausages, which should take about 6 minutes. Grill the lemon halves, cut-side down, on the grill for about 5 minutes. Transfer cooked sausage to a service platter and lightly cover with tin foil to keep warm as you continue grilling the remaining meats.
Cook the chicken thighs for 8 minutes or until completely cooked before transferring to a foil covered platter. Cook the lamb chops, 6 minutes for medium-rare, 8 minutes for well-done and transfer to a service platter. End by cooking the filet mignon 2 minutes per side for medium-rare, 3 minutes per side for well-done. Remember to check that everything is cooked with your thermopro thermometer.
Arrange the cooked meats in an attractive manner on a service platter with grilled lemons. Sprinkle it with chopped mint and serve with your favorite side dishes and suggested condiments.