Heat oil in large frying pan over medium-high heat. Add onion and capsicums. Cook, stirring occasionally, for 5 minutes or until starting to brown. Add garlic, paprika, oregano and cumin. Cook, stirring, for 30 seconds or until fragrant. Add mince. Cook, breaking up mince with a wooden spoon for 6 to 8 minutes or until browned.
Add tomato paste, stock and 1/2 cup water. Bring to a simmer. Stir in rice. Reduce heat to medium-low. Cook, uncovered, for 8 to 10 minutes or until liquid is absorbed. Top with sour cream, avocado, coriander and chilli. Serve with lime wedges.