In a pan, saute the onions, garlic, red pepper and rosemary together in olive oil. Allow onions to begin caramelizing and then set aside and allow to cool for a few minutes.
In a large bowl, add the cherry tomatoes, the onion mixture, 1 tb flour and salt and pepper. Mix well. Add tomato mixture into cast iron or baking dish.
To make the Gruyere biscuits, in a large food processor fitted with a dough blade, add the flour, butter, baking powder, heavy cream and salt. Pulse a few times until you see dough is "pea sized". Add cheese and rosemary and pulse a few more times just to mix though.
Form dough on a well flowered surface in a large square. Cut in half (you will have a lot of dough leftover). and Roll 1 of the squares with a rolling pin so it is about 1/2 in thick.
Use a round cookie cutter to make round biscuits and place biscuits on top of tomato mixture. Depending how large your dish is, you can decide how large you want your biscuits to be.
Brush biscuits with heavy cream and bake at 350 degrees for 35-40 minutes or until the biscuits begin to puff up and brown and the tomatoes break down.