Beef – substitute a top round beef roast with a beef rib eye roast

Eye of round is an excellent cut for braising. You can braise it in stock or red wine. An example recipe would be the classic Beef Bourguignon.

It's also a perfect candidate for slow-cooking in a crock pot, as well as simply roasted in the oven. If cooking it in the oven, use a thermometer and don't cook it past medium. An overnight marinade can be used prior to roasting for additional flavor as well.

To get more flavor out of cumin, you can use whole seeds, and toast them briefly in a pan before grinding. If you don't want to put forth that extra effort, you'll just need to add more cumin. If it's not salty enough, the best solution is to just add more salt (sorry). Salt will enhance the other flavors as well. A bit of cornstarch would help make the spices stick, and dry out the mixture. I'm not sure how much water and vinegar you're adding, but you may just be watering down your beef too much. I usually add just enough to keep the spices from sticking to the pan, but not so much that there is a lot of extra liquid that needs to be reduced.

Your spice mixtures may also contain some form of MSG. You can get a similar umami "punch" by adding a dash of Worcestershire sauce.

Edit: I don't know how I missed this, but the other answers point out the lack of garlic and onion. Your store-bought spice mixtures definitely contain plenty of those in powdered form, which you can use, but fresh is tasty too. Don't add fresh garlic too early, as it can easily burn and turn bitter.