Tip:You can substitute frozen corn for fresh. Let it thaw almost all the way and expect it to take a little longer to turn golden.
Put the lettuce and cilantro in a large bowl, cover with a damp paper towel, and refrigerate. In a small bowl, combine the onion, lime juice, honey, and fish sauce. Whisk in 1/4 cup of the oil. Season with 1/4 tsp. salt and several grinds of pepper.
Heat the remaining 2 Tbs. oil in a large nonstick skillet over medium heat until shimmerring. Add the corn and jalapeño and cook, stirring frequently, until the corn is golden, 4 to 5 minutes. Add the shrimp and cook until pink and cooked through, about 4 minutes. Remove from the heat, add 2 Tbs. of the dressing, and toss well.
Toss the lettuce and cilantro with the remaining dressing. Portion the greens onto four plates. Spoon the corn and shrimp evenly onto the greens. Serve immediately.
This salad makes a great wrap sandwich; just wrap portions of salad in warm tortillas.