Heat a large skillet over medium-high heat. Add corn kernels to the dry skillet and let char until kernels blacken, around 3-4 minutes, stirring rarely. Remove from heat and add to a large bowl.
Stir in the red bell pepper paste and lime juice and toss to coat. Sprinkle with salt and pepper and toss once more. Gently stir in the arugula, then adjust seasoning as desired. Sprinkle with optional cotija cheese, then garnish with serrano slices and cilantro and serve.
*in place of the red bell pepper paste, you can use oil-packed sun-dried tomatoes. Pat dry two and whiz them up in a blender with the lime juice. A little goes a long way, as the flavor is much stronger, so don't use too many.*omit the optional cheese to keep this dish vegan, but if you prefer a different cheese, feta makes a great substitute, especially if you use sun-dried tomatoes.