Soak the two lentils with enough water to cover by two inches for at least three hours or overnight.
To prep the potato skins, spray some oil on a baking sheet and place the potatoes on it, not touching each other. Spray some oil over the potatoes.
Preheat the oven to 400 degrees F and place the baking sheet with the potatoes on the middle rack.
Bake for 35 minutes or until the potatoes are cooked through and a knife pierced through the center goes cleanly through.
When the potatoes are cool enough to handle, cut them lengthwise in half.
Using a spoon or a melon baller (spoon works better for me), scoop out the potato flesh from the skin, leaving just a very slight layer of potato flesh on the skin. You can use the potato flesh to make mashed potatoes or something else equally yummy.
Place the skins back on the baking sheet, skin side down. Spray lightly with a film of oil, then turn them over so the skins are facing up and spray again.
Return the skins to the oven and bake 10 minutes. Flip the skins over and bake another five minutes until they are quite crisp.
While the potatoes are baking, make the filling.
Drain the lentils, wash them in running water, and then place them in a blender. Add the chipotle chili, garlic, cumin and salt to taste.
Add 1/2 cup of water and blitz. You want a smooth paste that's slightly thicker than pancake batter. If the mixture is too dry, add more water.
Remove the paste to a microwave-safe bowl and microwave on high for three minutes. Remove the bowl from the microwave, stir the paste which will have started to cook around the edges, and microwave again for another three minutes. Remove and stir again and microwave once more for two minutes.
By now you will have a nearly cooked paste. Let it cool completely and then, with your fingers, crumble it into small pieces, like you would crumble tofu.
Heat the oil in a wok or a large nonstick skillet and add the green peppers and spring onions to it. Add some salt and the black pepper and saute for about 5 minutes, stirring frequently.
Add the crumbled lentils to the wok and continue to stir-fry until the lentils start to crisp up and begin to assume a reddish hue.
Check salt, stir in the coriander, and turn off the heat.
Scoop some of the filling into each of the baked potato skins and return the baking sheet to the oven to warm everything up, for another five minutes.
Squeeze some lemon juice over the skins and sprinkle some of the reserved scallions over them.