Slice the baguette thinly (about 1 cm / 0.4 inch).
Heat a skillet medium-high.
Add the butter (or olive oil).
Once the butter is sizzling, top with the slices of bread until golden brown.
Then, turn over on the other side until golden.
Leave to cool.
To make the whipped feta, mix the feta, yogurt, lemon juice, and garlic in a mini food processor until creamy (you can also mix it by hand).
Add sea salt and pepper to taste.
Slice the mango as thinly (about 2-3 mm) and use the chick cutter to make the cutouts.
Repeat with the mozzarella.
Halve an avocado and remove the peel.
Cut the avocado in thin slices lengthwise.
Flatten out the pieces with the palm of your hand, ensuring they are still overlapping.
Use the chick cutter to make the fanned avocado chicks (you may need to use a small knife to lift them).
Assemble the crostini with whipped feta, avocado, mozzarella, and mango chicks.
Decorate with a few basil leaves and sesame seeds for eyes.
Sprinkle with sea salt and pepper.
Serve.