Husk 3 tomatillos. Cook in boiling water until tender, 2 to 4 minutes; drain, chop and transfer to a food processor. Halve, pit and chop 3 ripe avocados; add to the food processor along with 1/4 cup each sour cream, cilantro and mint, 1 grated small garlic clove, 2 teaspoons jalapeno hot sauce, the juice of 1/2 lime and 1 teaspoon kosher salt. Puree until smooth. Transfer to a bowl and season with more salt and cayenne.