Mix the cornbread mix, milk, butter and egg in a bowl until smooth. Coat a large, cast-iron skillet with the oil. Add the cornbread mixture to the skillet and, using your fingers, press it until it covers the entire surface area of the skillet. Bake until golden around the edges, 15 to 20 minutes. Let cool.
Mix together the ricotta, Asiago, Pecorino Romano and Parm in a small bowl.
In a separate skillet, brown the sausage over medium-high heat, crumbling the sausage with a spoon and cooking until golden brown and no longer pink. Drain on a paper towel, but reserve the fat in the skillet. Lower the heat to medium and add the greens. Season with salt and pepper and saute until wilted and cooked through, about 5 minutes. Let cool.
Preheat the broiler.
Smear a good layer of the cheese mixture on top of the crust. Top with the crumbled sausage and sauteed chard. Place under the broiler until bubbling and melted, 3 to 5 minutes. Top with the sliced peppers and serve!