Step #2 In a big pan cook the pasta as per packet with lightly salted water.
Step #3 Melt the butter & oil in a saucepan & to it add the bacon sliced into pieces.
Step #4 Cook for 2 mins.
Step #5 Stir in the flour & cook 2 more mins; remove this from the heat.
Step #6 Gradually stir in the the stock & milk, then return to the heat & cook, carefully stirring all the time until the sauce thickens; season to taste.
Step #7 Place the now cooked pasta in a shallow oven-proof dish & scatter the tuna on top.
Step #8 Toss lightly; pour over the sauce.
Step #9 MMx together the breadcrumbs & grated cheese & scatter over the top.
Step #10 Add herbs either fresh or dried--less if using dried.
Step #11 Bake in the oven for 20 mins or until golden brown.