Whisk the flour and baking powder together in a mixing bowl. Cut the margarine into the flour mixture with a knife or pastry blender until the mixture resembles fine crumbs. Fold the sunflower seeds and Parmesan cheese into the mixture. Add most of the milk and mix to a firm dough.
Turn the dough out onto a lightly floured surface and lightly roll to a thickness of 3/8 inch. Cut into 2-inch rounds and arrange on a baking sheet. Brush the tops of the biscuits with the remaining milk.
Bake in the preheated oven until the biscuits are lightly browned and no longer wet in the middle, about 20 minutes. Set aside.
Heat the oil in a large pot over medium-high heat; cook and stir the onion, carrots, turnips, yam, celery, and broccoli in the hot oil until the vegetables are soft, about 10 minutes. Season with the coriander, oregano, basil, salt, and pepper; add the tomatoes and vegetable broth. Simmer the mixture until hot and the liquid has reduced slightly, about 20 minutes. Serve in bowls topped with the mini-biscuits.