Preheat: Adjust rack to top position and preheat oven to 475 degrees.
Wash: Wash and dry all produce.
Cut: Core, deseed, and dice poblano. Finely dice tomato. Trim and thinly slice scallions, separating whites from greens.
Drain: Drain beans over a small bowl, reserving liquid.
Sautee: Heat a drizzle of oil in a large pan over medium-high heat. Add poblano and cook until just softened, 3-4 minutes.
Add in: Once poblano is just softened, add tomato, scallion whites, half the beans, 2 TBSP reserved bean liquid, and 1 tbsp. taco seasoning to pan.
Cook filling: Cook, stirring, until fragrant and warmed through, 2-3 minutes. Season with salt and pepper.
Make mashed bean : Heat a large drizzle of oil in a pot over medium-high heat. Add remaining beans and cook, stirring, until slightly softened, 2-3 minutes. Add 3 TBSP reserved bean liquid.
Simmer: Simmer until warmed through, 1-2 minutes. Reduce heat to low and stir in 1 TBSP butter
Mash: Turn off heat; mash with a potato masher or fork until mostly smooth. Season with plenty of salt and pepper.
Assemble: Spread tortillas with mashed beans. Place a small amount of filling on one half of each tortilla. Roll up tortillas, starting with filled side, and place seam sides down in an 8-by-11-inch baking dish or ovenproof pan.
Cover: Spoon enough salsa over enchiladas to generously coat. Sprinkle with Monterey Jack.
Bake: Bake on top rack until salsa is bubbly and cheese melts, 3-5 minutes.
Make crema: add sour cream to bowl with 1 tsp of taco mix. Stir in warm water 1 tsp at a time until mixture reaches a drizzling consistency. Season with salt and pepper.
Serve: Top baked enchiladas with crema, scallion greens, and as much chili as you like. Divide between plates and serve.
