Heat the oven to 425° F. and add 2 tablespoons of butter to a 10" cast iron skillet and put in the oven to melt the butter and get the skillet hot.
On a large cutting board, prep all the peppers and the tomato by seeding and dicing. Peel the onion and dice.
In a large mixing bowl add the cornmeal, flour, baking powder, baking soda, salt and pepper and whisk to combine.
Measure the buttermilk and beat in the three eggs. Pour this mixture into the dry inredients mixture along with the melted butter and lightly mix.
Add the corn, shredded cheddar cheese, and the green and red bell peppers. Mix together thoroughly.
Carefully remove the cast iron from the oven, it will be very hot. Pour the cornbread batter into the skillet. It will probably sizzle.
Add toppings, except the Cojita cheese. Bake the cornbread for 25-30 minutes at 425° F. until the bread is baked through and golden brown.
When the bread is done, remove from the oven and sprinkle with the crumbled Cojita cheese.
Serve warm. Store the leftover cornbread in a sealed container on the counter for two days.