Wash the peppers and cut off the top part, which includes the stem. Using a paring knife remove any seeds and pith.
Sweat the onion in oil until translucent. Set aside to cool.
Mix the ground meat with the cooled onion, minced garlic, salt, pepper, sweet paprika and egg.
Add in the rice and water and work the filling until it comes together into a smooth mass.
Put some filling in each pepper to reach about 3/4 of the volume (keep in mind that the rice expands). Place the stuffed peppers upright in a pot.
Use the rest of the meat filling to shape 4-5-cm- (1.5-in-) wide meat balls – these are called ćufte. Wedge them between the peppers.
Pour enough water to keep everything covered. Cook on medium heat for 30 minutes.
Make the roux by heating the oil. Mix in the flour and stir until it turns golden. Sprinkle in some sweet paprika and immediately pour in the tomato juice. Let it come to a simmer, then strain if there are any lumps left.
Pour the roux back into the pot with the peppers. Cook for 10 more minutes.
Serve with mashed potatoes.