In one small bowl, dissolve yeast in the warm water, put to the side to stand for 5-10 minutes.
Mash bananas in other small bowl.
In large bowl mix: oil, sugar, salt, and boiling water, stirring so it's all mostly dissolved.
4Add the cold water to the large bowl (the mix should be warmish now but not hot). Stir in yeast mix.
Add flour, one cup at a time.
Turn out onto lightly floured surface. Knead for 5-10 min, dough should be smooth, not too stiff or too runny.
Lightly coat the large mixing bowl in oil, turn the dough in it to just coat it with oil, place a towel over the dough in the bowl and let it rise for about 1 hr, till double in volume.
Punch dough down, turn out and knead again 2-3 minute Divide dough into 2 balls, divide each ball into 3 sections, roll each section into long ropes and make 2 braids. Preheat the oven to 350.
Let the braids rise 45 minute Boil a little more water. Just before putting braids in the oven, brush them with boiling water, then sprinkle with sesame seeds, poppy seeds, or sea salt.