Toast walnuts at 350°F for 8 to ten minutes, tossing halfway through. Cool, then crush into large pieces.
Heat 2 tbs oil in a large skillet, over medium-high heat. Cook peppers, shaking pan and turning peppers occasionally, 6-8 minutes.
Cool peppers and cut half lengthwise.
Combine ricotta with 2 tbsp oil in a small bowl, finely grate lemon zest over mix well.
Combine peppers, cucumbers, mint, and half of walnuts in a large bowl.
Juice the reserved lemon into a bowl, drizzle 2 tbsp of oil, season with salt and toss to coat.
Transfer mixture to a platter along with any juices on the bottom of the bowl. Dollop lemon ricotta over and top with remaining walnuts, drizzle more oil and season with black pepper.
