You might have to experiment with the measurements since I never actually measuring anything (I'm pretty good at eyeballing it) so you might have to play with the portions a bit.
1 banana (the riper you have it the sweeter it's be. we don't eat much sweet stuff so many times we use a greener one)
1/2 cup frozen strawberries
1/2 cup frozen blueberries
1/2 cup frozen mangos
1/2 cup frozen peas
1 cup low fat, plain yogurt
fat free half and half (I use enough to cover the fruit in the blender but you could use less too, non-fat milk could be used too)
I blend it all together and it's a smoothie. We might have a cup or so of it and the rest we throw in the freezer overnight (usually, I just use an old yogurt tub). The next day I pop the tub in the microwave for about a minute (just enough so it's not stuck to the side and you can see a little liquid but it's still mostly frozen).
Then I put that back in the blender with some milk (maybe 1/2 cup?) and it tastes like soft serve ice cream!
I think you could even get away with adding more peas since they seem to be pretty unnoticeable with all the other fruit. We also just whatever fruit is available in our freezer (or about to go bad that is not in the freezer) so the measurements are definitely not set in stone.
Homemade "icecream"
