Soak beans with a good amount of water overnight. Once soaked, drain and rinse. Place the beans in a large pot and cover with fresh water. Add 1 tsp salt. Place on the stovetop and bring to a boil; then, reduce flame. Simmer for 1 hour, or until desired tenderness is reached. Stir the beans a few time so they don’t stick to the bottom. Drain most of the water, leaving about 1/2 inch at the bottom. Add 1 Tbsp olive oil, minced garlic, 1/4 tsp cumin, a pinch of salt and pepper. Cook for a couple minutes, stirring constantly; then, remove from heat, cover and set aside.
Using a mandolin or sharp chef’s knife, slice broccoli stem into paper thin rounds and cabbage into thin strips. Transfer to a medium bowl and mix in the scallions, 1 Tbsp olive oil, lime juice and 1/4 tsp of salt. Squeeze and massage the cabbage with your hands to help it release its liquid and begin wilting. Set aside.
Slice patty pan squash into thin rounds. Heat 2 Tbsp olive oil in a large skillet over a medium-high flame. Add the squash and cook, stirring only occasionally, until golden brown, about 10 minutes.
Set a large pan over a medium-low flame. Arrange 2-3 tortillas in a single layer. Flip them after 30 seconds or so. As they come off the stove, wrap them in a clean tea towel to keep them warm. Repeat with a second batch. Fill each taco with black beans and zucchini. Top with cabbage slaw and fresh herbs, if desired.