Some altnatives to the usual sweet suspects taking into account the allowable foods from steps 2 and 3:
Chargrilled/dry fried/baked chicken cubes with a cold yogurt, cucumber and dill dipping sauce (tzatziki)
Red lentil dhal with a scoop of yogurt on top
Prawns tossed a yogurt, paprika, chilli powder and a touch of watercress as a dressing
Mashed celeriac with a scoop of yogurt for creaminess
Asparagus (boiled for 60 seconds then put in an ice bath) with a yogurt based hollandaise sauce -
Yogurt Hollandaise Sauce Recipe - Food.com - 368990
Chicken stuffed with mushroom, leek and spring onion yogurt sauce then baked in an oven
Quorn mince, grated courgette, green pepper, celery with a scoop of yogurt and mixed herbs and spices...one pan and a little water
Spiced yogurt and chickpea hummus
Some of these require more work and effort than you really want to do given the small portion sizes permitted but it depends on how much you enjoy cooking with those options...or make in bulk.