Step 1 Fry the bacon in a hot skillet until done but not too crisp, about 8 minutes. Drain on paper towels and set aside.
Step 2 Cut the avocados into quarters or sixths. Sprinkle lightly with lemon juice, add the chives and toss. Season with sea salt and pepper. Set aside in a serving dish.
Step 3Cut the tomato into slices about one-fourth-inch thick and season lightly with sea salt and pepper. Set aside. Cut the red onion into very thin (about one-eighth-inch) slices and season lightly with sea salt and pepper. Set aside.
Step 4Crumble the blue cheese and cheddar into separate serving bowls. Slice the Gruyere with a cheese plane onto a serving plate and set aside.