from kitchn.com, serves 6-8
4 pints cherry tomatoes (3 1/2 to 4 pounds)
1/2 tablespoon olive oil
2 red onions, peeled and thinly sliced
1 1/2 teaspoons salt, divided
4 cloves garlic, minced
1/4 cup red wine (or 2 tablespoon balsamic vinegar)
1/4 cup all-purpose flour
For the biscuits
1 1/4 cup all-purpose flour
3/4 cup cornmeal
1 tablespoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
6 tablespoons cold unsalted butter
1 cup + 1/2 cup grated cheddar cheese, divided
3/4 to 1 cup buttermilk, plus extra to brush
1. Heat the oven to 375°F.
2. Warm olive oil in a 12-inch cast-iron or high-sided stainless steel skillet over medium-high heat. Add the onions and 1/2 teaspoon of salt. Sauté until the onions are very soft and tender, at least 10 minutes.
3. Stir the garlic into the onions and cook until fragrant, 30 to 60 seconds. Pour in the wine (or balsamic) and cook until the wine has mostly evaporated. Stir in the flour and cook until the flour is paste-like. Remove the pan from heat. Stir in the cherry tomatoes and 1 teaspoon of salt.
4. To prepare the biscuits, combine the flour, cornmeal, baking powder, baking soda, and salt in the bowl of a food processor. Pulse a few times to combine. Cut the cold butter into chunks and scatter it over the flour. Pulse a few times until the butter has been cut into pea-sized pieces.
5. Transfer the flour-and-butter mixture to a bowl and stir in 1 cup of the cheddar (reserve the other 1/2 cup for sprinkling over the top). Form a well in the middle and pour in 3/4 cup of buttermilk. Use a spatula to gently stir the buttermilk into the flour until all the buttermilk has been incorporated and no more dry flour remains.
6. Drop the dough over the tomatoes, making 7 to 8 biscuits. Brush the biscuits with a little buttermilk. Place the skillet on a baking sheet to catch drips, and then transfer to the oven. Cook for 55 to 60 minutes, until the tomatoes are very bubbly and the tops of the biscuits are nicely browned. About 10 minutes before the end of baking, sprinkle the tops of the biscuits with the remaining 1/2 cup of cheddar. Remove from the oven and let the cobbler rest for at least 15 minutes before eating.