Dissolve the yeast in an eggshell full of lukewarm water and combine all ingredients, except the water. Pour the water into the mixture until a pliable dough ball is formed. Pay attention, sometimes you just need a little less water. Knead the dough for at least 10 minutes on a worktop dusted with flour or in a food processor until smooth and silky. Leave to rise for one hour. Roll the dough into a thin sheet (you might have to cut it in half), place on baking paper and then on a greased baking sheet. Lightly cover with water and sprinkle with seeds or salt to garnish. Do this in nice strips, for example. Bake the dough in an oven preheated to 175°C (340°F/Gas 4) for 12–15 minutes or until the crackers turn an even golden brown. Break into equal parts and serve with dips and sauces.