In a large pot, heat the olive oil over medium heat. Add the chopped onions and garlic, and sauté until the onions are translucent, about 5 minutes.
Add the diced chicken to the pot, seasoning with salt, pepper, and dried thyme. Cook until the chicken is lightly browned, about 7–10 minutes.
Stir in the honey and Dijon mustard, mixing well to coat the chicken.
Pour in the chicken broth and bring the mixture to a gentle boil.
Once boiling, reduce the heat to low and add the quartered radishes, allowing the stew to simmer for about 30 minutes.
Stir in the diced cucumber and continue to cook for another 10 minutes until all the vegetables are tender and the chicken is fully cooked (internal temperature should reach 75°C / 165°F).
Taste and adjust the seasoning, if necessary.
Serve hot with a sprinkle of chopped cilantro and a crack of black pepper on top.