Heat oven to 200C/180C fan/gas 6.
Sit the chipolatas in a roasting tin and
cook for 15 mins.
Meanwhile, pop open the crossiant
packs and unroll. Mix the onion
marmalade, tomato purée and mustard,
and spread some over each dough
triangle. When the chipolatas are done,
set aside for 5 mins to cool while you
line 2 baking sheets with baking
parchment. Lay a sausage along the wide
end of each triangle croissant and roll up,
encasing the sausages. Arrange on the
sheets, brush with beaten egg and
scatter with sesame seeds. Bake for
10-15 mins, switching shelves halfway,
so both sheets cook evenly, until golden.