How to Make It
In a mini food processor, combine the olive oil, serrano chile, dill, chile powder and a generous pinch of salt and pepper and puree. Transfer the marinade to a bowl and add the sliced meat, turning to coat. Let stand for 10 minutes.
Meanwhile, rinse out the food processor. Add the garlic, shallot, vinegar, Worcestershire sauce and hot sauce and process until the garlic and shallot are finely chopped. Add the mayonnaise, sour cream and milk and process until smooth. Add the blue cheese and pulse once or twice to combine. Transfer the dressing to a bowl and season with salt and pepper.
Preheat a grill pan. Grill the beef tenderloin slices over high heat for 5 to 6 minutes, turning once, for medium-rare meat.
Arrange the lettuce, tomatoes, cucumber, red onion and hard-cooked eggs on plates and drizzle with the dressing. Arrange the beef tenderloin slices on the plates and serve.