Wash the potatoes and boil with the skin; in the meantime, transfer the couscous in a bowl, pour over 130 ml of boiling water slightly salted and 1 tablespoon of oil and let it swell often stirring with a fork.
When the potatoes are cooked, peel, mash with a potato masher and add in a bowl the puree obtained with couscous, a pinch of salt and pepper and the spinach chopped with a knife.
Divide the mixture into 4 large croquettes of the same size, lay them on a plate covered with oven paper, brush with a little oil and place in the center of each croquette a cherry tomato.
Bake in preheated oven for 10 minutes. Mix the yogurt in a bowl with the drained and chopped pink pepper, a drizzle of oil and a pinch of salt and use it to accompany the croquettes.