Stir cottage cheese and drain loose whey in a fine sieve for 5 minutes only if needed; season with pepper.
Salt diced seeded tomato in a sieve for 10 minutes, blot and fold in basil.
Slice avocado near serving and coat lightly with lemon juice.
Brown mushrooms in 1 teaspoon oil for 4 to 6 minutes until dry; add thyme, garlic and salt for 30 seconds.
Brush bread with oil and toast deeply until both faces are golden and the centers crisp.
Add 1/4 cup cottage cheese to each hot toast, leaving a narrow border.
Finish two with tomato and balsamic, two with avocado, chile and salt, and two with mushrooms.
Serve on an open platter within 10 minutes and do not stack.