I always buy ripe bananas as they are usually cheaper than the unripe green crap.
Sometimes they are so ripe I can only mash them as they would not even slice :) but I love their sweetness.
This "mash" can be used as a dressing on greensalad leaves (rocket, watercress etc) or it can be used as a base for a fruit salad.
You will be surprised how little amount of mash will one banana produce - usually I use 5-6 bananas to do this.
5 ripe bananas
1 large lemon or two limes (juice and zest)
2 tablespoons of walnut or coconut oil (or any other nut oil)
2 tablespoons of raw agave syrup (or zylosweetor anything else you like to use)
a pinch of pink Himalayan salt
ground cinnamon, cardamom or any other sweet spice you have to taste
Peel and mash the bananas - I use my old potato masher for this.
Add all the other ingredients and mix well. It will oxidize as time goes but the taste will be better.
I use it as it is to dress green salads or mix in any diced / slicedfruit for an unusual fruit salad. It tastes great with strawberries, mangoes, pears or apples.
You may add a bit of cayenne if you would like a kick; a bit of sumac or mango powder will make it sour. Sometimes I add a bit of fresh ginger.
Also, when Iprepare it with mangos or pears I usually add some chopped mint leaves as well - it tastes and looks great with the green bits.
You can add diced fresh pineapples and coconut flakes (yum).
Really, the possibilities are endless, just use your imagination(and your leftover fruit).