Prepare the dough by mixing flour, salt, and baking powder.
Add water and olive oil to the dry ingredients, stirring until a dough forms.
Wrap the dough in plastic wrap and let it rest for 30 minutes at room temperature.
While the dough rests, preheat your grill or skillet over medium heat.
Roll out the dough into thin rounds (about 1/8 inch thick).
Cook the flatbreads for 2-3 minutes on each side or until lightly browned.
In a bowl, combine asparagus, radishes, peas, herbs, lemon zest, and juice.
Top the cooked flatbreads with the veggie mixture and feta cheese if using.
Serve immediately, garnished with additional herbs if desired.
