Can salad dressing be made with coconut oil? Does one need to blend it to homogenize it? Will coagulation of occur afterwards?At room temperature, coconut oil is not liquid like vegetable oils. 
Like bananas, plantains (platano macho in Spanish) start out green and ripen from there. When ripe, they indeed have black peels, and are softer and sweeter. But when not very ripe, the peel is green to yellow-green, and they're harder and just starchy, not sweet.  So, they require some amount of cooking to soften enough to eat, but they don't require a special cooking technique or anything - roast them, fry them, stew them, whatever you like. Thinking of them as vaguely similar to potatoes isn't a bad approach. You can find plenty of recipes online.  As for why I think it's specifically a plantain, not just a green banana of some other kind:   you implied it was like a plantain, except with green skin and not sweet the shape, in particular the thick elongated bit on the bottom, looks like a plantain; other bananas usually come to a shorter end you don't mention any sourness  