Nancy those jars are jelly jars and in most stores right now as there are a seasonal item. Great for multi use. I put peanut butter in them for kids lunches.

Otherwise, to make up an egg, I use a ceramic bowl, drop i egg, whisk, add extras or not and microwave. For a change of pace. The sizing is different: flat and wide round. Makes for quick egg salad. A ceramic mug works too.

I envy you your silicon option-- will be loads of fun to trial those babies!!