Preheat the oven to 200°C.
Place the red bell peppers on a baking tray lined with parchment paper. Drizzle them with 1 tbsp of olive oil.
Cut the top off the garlic bulb, drizzle it with 1 tsp of olive oil, and sprinkle with salt, black pepper, and chilli flakes. Wrap the garlic in aluminium foil and place it on the baking tray alongside the bell peppers.
Bake for 50 minutes, flipping the bell peppers halfway through.
Once cooked, transfer the bell peppers to a bowl and cover with a lid or cling film. Let them sit for 10 to 15 minutes, covered, as it will make it easier to peel off the skin.
Deseed and peel the skin off the bell peppers, then transfer them to a food processor.
Add the squeezed garlic, olives, feta cheese, Tabasco, remaining olive oil, black pepper, salt, and basil to the food processor. Blitz until smooth.
Transfer the dip to a serving plate, drizzle with olive oil, and sprinkle with paprika, Nigella seeds, and basil leaves.