Place tomatillos, onion, and serrano on a hot sautee pan. Char all vegetables until nice and toasty. Blend with cilantro and season to taste.
Combine the warm water, yeast and sugar in a small bowl. Put the bowl in a warm, not hot or cool, place until the yeast is bubbling and aromatic, at least 15 minutes.
Get Creative! : feel free to top with kalamata olive, sundried tomato, oven roasted tomato, garlic cloves confit, herbs maldon flake salt, fleur de sel, black pepper, herbs