For the panini bread:
1) In a bowl, combine the yeast and water. Let sit for a couple of minutes until the yeast is foamy.
2) Add the olive oil and caster sugar and mix well. Combine the salt and plain flour and add a cup at a time to the wet mixture, mixing until it forms a dough.
3) Turn the dough onto a lightly floured board or counter and knead repeatedly for about 4 to 5 minutes. Put the dough in a greased bowl, cover with a towel and let it rise for about 1 hour or until it has doubled in size.
4) Punch down the dough then let it rise for another 30 minutes.
5) Preheat oven to 200C/Gas 6.
6) Punch down the dough again and separate into two portions. Roll each section of the dough out into a rectangular shape about 1 1/2cm thick. Make indentations on the dough with your fingertips. Lightly rub the dough with olive oil and sprinkle grated parmesan cheese over the top.
7) Bake in the hot oven for approximately 20 minutes. Ovens vary so keep your eye on the bread. When it's done, remove from the oven and let cool.
For the bourbon sultana sauce:
1) In a frying pan over low heat, pour in the bourbon whisky. Add the cream cheese and mix until well-blended with the bourbon.
2) Add the sultanas, maple syrup, salt, allspice and double cream. Mix well. Allow the mixture to simmer over very low heat for a couple of minutes. Set aside.
For the lamb:
1) In a frying pan, melt 60g of butter over low to medium heat. Add the chopped lamb chunks and stir.
2) Add the onions and peppers, mix well and saute the mixture over a low heat for 5 minutes.
3) Add the cheese to the mixture and cover (partially) with a lid.
For the assembly:
1) Slice each panini in half crosswise then in half again, separating the top from the bottom. Butter each slice with the remaining butter and griddle to desired crispness. Put the bottom of the bread slices on four plates.
2) Add 250ml or more of the bourbon sultana sauce to the lamb mixture, keeping some aside to put in ramekins for a side of sauce when serving the sandwiches. Mix well.
3) Evenly distribute the lamb mixture onto the toasted bread. Evenly distribute the mesclun greens and tomatoes over the lamb. Cover with the top slice of bread.
4) Serve immediately.