Preheat oven to 400 F. Place the olive oil on the bottom of an oven safe dish.
Cut tomatoes in half and sprinkle salt and pepper on the cut side. Place cut side down in the dish along with the garlic and thyme.
Roast in oven for 1 hour.
Leave to cool and meanwhile prepare the crostini.
Slice the bread - about 3 slices per person.
Brush the bread with olive oil.
Place underneath the broiler for about 3 minutes on each side, until golden brown.
When the tomatoes are cool enough to handle, chop them and add basil.
Mix well and let sit for 30 minutes to let the basil flavor infuse into the tomatoes.
To make the bruschetta, place a little of the tomato topping on the crostini and serve.
To make the pesto sausage bruschetta, brush the crostini with a little pesto.
Add sausage and cheese on top,
Put underneath the broiler for a few minutes, until the cheese melts.