Drain the beans in a sieve.
Add 600ml water, the beans, the tinned cherry tomatoes, the pasta, the spice mix and ½tsp salt to a large pot. Bring to a boil and then turn down the heat to medium-low. Cover with a lid and cook for 12–15min., stirring occasionally, until the pasta is al dente.
Meanwhile, crumble the feta into large pieces.
After about half of the cooking time, add ⅔ of the feta and 2Tbsp milk to the pot. Continue to cook everything for the remaining minutes, so the cheese melts and the sauce becomes creamy. Add more water, if necessary, to reach the desired consistency. Taste and add salt if desired.
In the last minute of cooking, add the spinach to the pot and let it wilt into the sauce.
Divide the pasta over bowls or plates and serve the pasta sprinkled with the remaining feta.