Heat a cast iron skillet over medium heat. Add walnuts to the dry pan, and cook, stirring frequently, until golden brown and fragrant. Transfer to a cutting board and roughly chop.

Add 2 tablespoons olive oil to the cast iron skillet, and turn the heat up to medium high. Add peppers and cook, turning occasionally until skins are charred and peppers are tender.

Meanwhile, zest lemon into a small bowl. Add ricotta cheese and 2 tablespoons of olive oil. Season with salt and stir until fully combined.

In a large bowl combine charred peppers, cucumbers, and mint. Slice lemon in half and squeeze juice into bowl. Toss to coat.

Transfer pepper mixture to a platter. Dollop ricotta cheese over the top and sprinkle with toasted walnuts. Drizzle with remaining 2 tablespoons olive oil. Serve.