Prep the “cups”: Slice each mini pepper in half lengthwise; scoop seeds. Arrange on a platter, cut-side up.
Cook the turkey: Heat avocado oil in a large skillet over medium-high. Add turkey, breaking it up. Cook 5 min until mostly browned. Sprinkle taco seasoning; pour in water/broth. Simmer 3 min, stirring, until liquid reduces and meat is saucy.
Fill & melt: Spoon hot turkey mixture into pepper halves. Sprinkle cheese over each. Cover loosely with foil 2 min so cheese melts from residual heat.
Finish & serve: Add avocado cubes, a dollop of salsa or sour cream, and cilantro.