Preheat the oven to 190 C / Gas 5. Place the potatoes in a bowl and microwave for 3 minutes.
In a large frying pan heat some oil to medium and add the potatoes. Cook, stirring often for until brown and starting to crisp, about 10 minutes; set aside. In another large nonstick frying pan add the chorizo and cook over a medium heat until you see some of the fat being released. With a slotted spoon remove and set aside.
Add the onion to the pan, add a little oil if needed. Cook until translucent. Add the peppers and garlic and cook over a medium heat, stirring often for aboiut 5 minutes. Add the tomatoes and paprika and cook until reduced slightly and mushy, about 5 minutes. Return the chorizo to pan and add the potatoes. Mix well. Distribute evenly between the oven proof individual dishes.
Bake in the oven for 3 minutes. Remove and make a hollow in the middle of each dish. Carefully crack an egg into the middle. Dot with a little butter and return to the oven. Cook until the whites are set but the yolk still runny, 6 to 8 minutes. Remove from the oven, season and serve with crusty bread.
You can make ahead all steps apart from the eggs going in. Chill until needed. Remove from the fridge 1/2 hour before baking and proceed with baking in oven for 3 minutes and then adding the eggs.