How to Make It
Toss together tomato, radishes, onion, oil, lime juice, vinegar, and 1/4 cup of the cilantro in a bowl.
Place cheese in a medium saucepan. Sprinkle with cornstarch; toss to combine. Add evaporated milk. Cook over medium-low, whisking often, until cheese melts and mixture thickens, 4 to 8 minutes. Whisk in salt.
Arrange chips in a single layer on a large serving platter. Drain tomato mixture; discard liquid. Top chips evenly with drained tomato mixture, lobster, and avocado. Drizzle evenly with cheese sauce. Sprinkle with remaining 1/4 cup cilantro.