Arrange the bacon slices between a double layer of paper towels on a microwavable plate. Microwave on high for 2 ½ to 3 ½ minutes, until crispy.
Pour the pumpkinseeds into a small skillet and set over medium heat. Once the first one pops, stir constantly until all have popped from flat to round, about 5 minutes. Scoop about 1/3 of them into a blender jar and add the lime juice. Pour the remainder into a small dish.
Return the skillet to medium heat and measure in the oil. Add the garlic and optional chile. Cook, stirring regularly, until the garlic is soft and lightly browned, about 5 minutes. Scrape the oil and garlic into the blender or food processor. Add the honey and ½ teaspoon salt. Process until smooth. Taste and season with more salt if you think necessary. (It should be highly seasoned.)
Divide the lettuce between 4 dinner plates. Pit and the avocados, scoop flesh from the skin and cut it into slices. Peel the mango, then cut the flesh from the pit. Slice to match the avocado pieces. Arrange the avocado and mango in the center of the lettuce. Drizzle everything with the dressing, then sprinkle with the cheese and toasted pumpkinseeds. Crumble the bacon and strew it over the top, and the salad is ready.
A Few Simple Riffs: Bacon can be replaced with flaked hot-smoked salmon, eel, trout or other fish. Leave out the bacon to make the salad vegetarian, or replace it with pan-grilled onion slices. The pumpkinseeds can be replaced with pinenuts (they toast—and burn—much faster than the pumpkinseeds). The luscious texture of mango works well with avocado, but so would ripe peach or nectarine. The green chile could be replaced by hot ground red chile (like árbol)—sprinkle it over the salad rather than blending it with the dressing. Crumbled goat cheese is a good stand-in for Mexican queso fresco.
Over-the-Top Crab-Avocado-Mango Salad: Sprinkle a generous portion of crab over the avocado and mango before drizzling with dressing.