Preheat the oven to 160°C.
Spray the frying pan with low-calorie cooking spray and place over a medium heat. Sauté the onions for 6-8 minutes until browned.
Add the beef mince and garlic and fry for 2 minutes until browned.
Add the bulgur wheat and stir in the stock. Bring to a boil then reduce the heat to a simmer. Cover and cook for 10 minutes.
Fluff up the bulgur wheat and stir in the lemon juice, chopped herbs and grated carrot. Taste and season with salt and pepper, if needed.
While the bulgur wheat is cooking, mix together the passata, water, Henderson's relish, garlic granules and onion granules, and pour into the bottom of the casserole pan or dish. Place to one side.
Prepare the peppers. Lay each pepper on its side and slice off the stalked top, but don't discard. Remove the seeds from the cavity of the peppers. If the peppers are too wobbly to stand up on their end, take a very thin slice off the bottom to level it out, but be careful not to slice through into the cavity.
Stand the peppers up in the casserole pan, on top of the tomato sauce and fill each to the brim with the beef and bulgur wheat mixture. If your peppers are smaller you may have a little mix left over. You can use this to fill another pepper, or keep it for lunch with some mixed salad and feta.
Pop the tops of the peppers back on and cover the pan or dish with a lid or some tightly-fitting tin foil.
Place in the oven for 45 minutes, then increase the oven temperature to 200°C. Remove the lid and cook for a further 15 minutes to allow the peppers to colour.
Remove from the oven and crumble over the feta. Serve!