Preparations: 

Chicken nuggets:

Pan/fryer: Heat oil to 180°. Cook the nuggets for approx. 4 minutes. 
Oven: Pre-heat the oven to 200°. Warm the nuggets for 12-15 minutes.

Beets and carrots:

Pre-heat oven to 185°.
Peel and cut beets and carrots into sticks. Put them in a ovenproof dish and season with oil, salt and pepper. Bake for approx. 40 min at 185°.

Dressing:

Chop the chives.
Mix the chopped chives with the greek yoghurt, buttermilk, mayonnaise, lemon juice, mustard and garlic powder. 

Slider:

Heat the buns in the oven for 2-3 minutes. 
Cut the red onion into thin slices.
Spread some dressing on the bun. Assemble the nuggets by placing some baby spinach, a nugget and a piece of slices onion. 

Serve.