In a saucepan over medium heat, warm the kefir gently. Avoid boiling. Lower heat if necessary.

Once curds begin to form, stir gently (less stirring yields larger curds). Let sit undisturbed once curds form.

When the whey turns slightly green, remove from heat. Add a pinch of salt and let sit for 5–10 minutes.

Strain the mixture over a bowl using a fine-mesh sieve or cheesecloth for 5 minutes. Chill for at least 1 hour.

Toast sourdough in a skillet with olive oil over medium heat until golden on both sides.

In a food processor, blend the chilled ricotta with olive oil and olive brine until smooth.

Spread ricotta onto the toasted sourdough. Top with tomato slices and avocado.

Finish with a sprinkle of flaky salt.