Lightly oil and flour two 450g loaf tins.
Sift flour, yeast, and sugar into a bowl and gradually mix in water to form a dough.
Knead dough for 5 minutes until smooth, then cover and proof in a warm place for two hours.
Add salt, knead for 3 minutes, shape into two loaves, place in tins, and proof for one hour while preheating oven to 220°C.
Bake loaves for 40 minutes until golden and hollow-sounding, then set aside to cool.
Fry shallots in oil until soft, then simmer with tomatoes, dates, tamarind, and spices for ten minutes.
Blend the mixture until smooth, sieve into a pan, and boil with vinegar, mustard, molasses, and sugar.
Stir in cornflour paste and cook for one minute until thickened, then leave to cool.
Slice buttered bread and assemble sandwiches with grilled bacon and brown sauce.