Turn on broiler. Place poblanos on a baking sheet and broil until blackened on both sides (about 8 to 10 minutes per side).
Remove from oven and immediately wrap in a towel or seal in a paper bag. Let peppers sweat for about 20 minutes or more, or at least until they're touchably cool.
Peel poblanos -- their blistered skin should slip right off. Remove seeds and cut peppers into bite-sized strips.
Peppers may be roasted, peeled and seeded up to a day ahead. Wrap and refrigerate.
Preheat oven to 400 degrees.
Spread cubed pumpkin in a rimmed baking dish. Drizzle with 1 tablespoon of the olive oil. Sprinkle with sea salt and freshly ground pepper. Roast for 25 minutes or so, stirring occasionally to cook evenly and prevent sticking.
In the meantime, heat remaining tablespoon of oil in a large skillet over medium-high heat. Add onions and garlic and cook, until softened and golden, about 8 minutes. Add epazote or oregano and thyme, chopped chilis and sage.
Reduce heat to medium. Add roasted pumpkin and the fresh spinach by the handful.
Combine gently until the tortilla filling is heated through and spinach is just wilted but still bright green -- about 5 to 7 minutes.
Season with sea salt and freshly ground pepper.
To warm tortillas, wrap in kitchen towels and steam them on top of a double boiler for a minute or two or wrap in foil and place in a 300 degree oven for a couple of minutes.
Mound filling onto tortillas and enjoy just like this, or with guacamole and a splash of a hot sauce.
Serves 6 to 8.