Slice and pickle them! Pickled jalepenos are better than fresh imo, and they will keep for a very long time. The perfect nacho is a tortilla chip with a slice of pickled jalepeno covered with cheese and melted.
Here's a recipe (this is for 1lb of peppers, you will need to scale this down to at least 1/2 for such a small amount)
1 lb fresh jalapenos, washed, sliced and stems removed
1 cup vinegar
1 cup water
1/4 cup olive oil
1 teaspoon salt
1 teaspoon pickling spices
Directions:
1 Pack peppers into clean, sterilized jars, leaving a few inches at the top.
2 Bring vinegar, water, oil, salt, and pickling spice to a boil in a saucepan over medium heat, stirring to dissolve salt.
3 Pour boiling sauce over peppers, leaving at least 1/2" headspace at the top of each jar.
4 Place caps on, and screw on lids firmly.
5 Process in boiling water bath for 20 minutes.
6 Remove bands when cool.
7 Check jars seals before storing; any that don't seal, refrigerate promptly.
8 Age several weeks before using.