1. Rinse the cherry tomatoes, keep some whole with the stems for each verrine and cut the rest into quarters.
2. Slice the shallot and sauté it in a pan with 2 tablespoons of olive oil. Add the chopped cherry tomatoes, sherry vinegar, brown sugar, Espelette pepper, and fleur de sel. Season with pepper, mix, and let simmer gently for 20 to 30 minutes until the liquid evaporates. Let cool.
3. In a bowl, crumble the feta with a fork and add the Greek yogurt. Mix vigorously to obtain a creamy, almost mousse-like texture. Season with pepper.
4. Bake the whole cherry tomatoes in the oven at 200°C for a few minutes, until they slightly soften without bursting.
5. Fill the verrines with the chutney and feta mousse, garnish with the softened cherry tomatoes, and sprinkle with a little fleur de sel.