In a dry skillet over medium heat, toast the sesame seeds until a deep golden brown and fragrant, tossing regularly to ensure they do not burn. Transfer them to a large, shallow bowl.
Heat 1 tablespoon of vegetable oil and 1 teaspoon of sesame oil in a medium saucepan over medium-high heat. Once the oil is glistening, add the corn and allow it to roast for 8 to 10 minutes. Stir the corn occasionally, but allow it to sit so it can char slightly. Set aside to cool.
To the bowl with the sesame seeds, add the garlic, lime juice, remaining sesame oil and vegetable oil, red pepper flakes, salt, and rice vinegar. Stir vigorously until the salt is dissolved.
Add the corn, avocado, cucumber, red pepper, shallot, scallions, half of the queso (about 2 tablespoons), and half of the cilantro. Toss to combine and add more salt to taste. Allow the salad to rest in the refrigerator for at least 3 hours to allow the flavors to meld.
To serve, top with the remaining queso fresco, cilantro, and any additional scallions.