When DS was around 10, I started making this on bonfire night (or as close to it as possible). He was okay with mild to medium spiced things at that age. If you don't like it too hot, miss out the cayenne pepper, it is just as nice without it and still spicy but not hot!
For 2 people you will need:
2 medium potatoes, halved lengthways then cut criss cross patterns on the top of the cut side
4 thick sausages
Into a mug put:
4 tablespoons of tomato ketchup
1/2 tablespoon vinegar
1 tablespoon oil
1 tablespoon soy sauce
1/2 tablespoon Worcestershire sauce
1/2 - 1 garlic clove, peeled and crushed
1/2 level teaspoon salt
1/4 level teaspoon cayenne pepper
Stir together well.
Using an oven pan/tray appropriate size for the numbers you are cooking for, lightly grease it and lay the potatoes and sausages in it and spoon half the spice mixture onto the top of each thing:
Remove foil, shake everything around and baste with fat if any visible. I found mine had rather frazzled away so changed pans. Top everything with the other half of the sauce: