Loaded nachos

2 tbsp olive oil

25g butter

450g fresh mince

1 Oxo cube

1 small onion, diced

1 green pepper, diced

1 garlic clove, crushed

1 tsp chilli powder

1 tbsp dried oregano

1 tbsp tomato purée

300ml water

Salt and freshly-ground pepper

500g tortilla chips

100g red cheddar, grated

Handful of sliced jalapeño peppers

For the sauce

10 tbsp mayonnaise

1 tbsp fresh cream

2 tbsp tomato ketchup

1 tsp mustard

1 tsp Worcestershire sauce