This is my grandmother's Cuban picadillo (ground beef hash/chili) recipe which is usually served with white rice, beans and plantains. Picadillo also goes great with mashed potatoes and can be made without the squash. This dish is a favorite at home so I usually make 2 pounds to have leftovers for making empanadas (meat pies) the next day. Picadillo also freezes well. Of course my kids say this is the best picadillo they've ever had and I have to agree!
Use another type of squash if butternut is not available.
Substitute a pinch of saffron or a dash or yellow food coloring for the sazon packet if preferred.