Heat oven to 425°

Grease a medium ovenproof skillet (non-cast iron) with olive oil or butter

Cut the butter into cubes

Beat egg in a small bowl

Put flour, cornmeal, baking powder & soda in a food processor with a sprinkle of salt

Add cubed butter & pulse until the mixture looks like coarse bread crumbs

Add the beaten egg & buttermilk, pulse into a thick, sticky batter

Halve the cherry tomatoes; put them in a medium bowl

Peel &I thinly slice the garlic, add to the tomatoes

Trim, peel, halve & slice the red onion; add it to the tomato mixture

Drizzle the tomato mixture with some olive oil, sprinkle with salt & pepper; toss

Put tomato mixture in the skillet & spoon dollops of the biscuit batter across the top

Bake until the biscuits are golden & cooked through, and the tomatoes & onion are softened, 20-25 minutes

Sprinkle with Parmesan &I torn basil leaves

Drizzle with olive oil

Serve hot, warm or at room temperature