First the recipe ingredients, then I'll explain the system...
3/4 c orange juice
1/4 c soy sauce (to keep it gluten-free, we use La-Choy, which is GF at the time of this post)
2 T. brown sugar
2 T. prepared yellow mustard
1 T. olive oil (the recipe card says canola, which you could use, we just use olive oil here)
2 garlic cloves, minced
1 1/2 -2 1/2 lbs beef roast (fat trimmed off edges if you desire)
Freeze for future use or cook thoroughly. (Personally, we have thrown these frozen solid from our deep freezer into our 8 quart Instant Pot with 1 cup water if the marinade didn't thaw yet and set them to manual/high/90 minutes and found them absolutely delicious and fall-apart tender. That's using a boneless arm roast, and you may have a different experience. Just make sure it's cooked safely to your liking.)
2 c beef cooking stock/broth
3-4 T. dry minced onion (I used 4 T. because that equates 1/4 cup so it is faster to scoop out)
1/2 tsp. onion powder
pinch celery seed
1/2 tsp. oregano
1/2 tsp. garlic powder
1/4 tsp. basil
Freeze for future use or cook thoroughly.
The process to prep LOTS of beef roast dumps for the freezer:
Step #1: Set out all of your ingredients, and if possible, set the appropriate measuring cup/spoon next to each ingredient. This makes things go efficiently.
Step #2: Get your roasts out and into 1 gallon ziplock bags. Placing the roast in the bottom first should help the bag stay upright so you can dump the marinade in.
Step #3: Following the recipe, dump each of the ingredients into a measuring cup (2 cups or larger) for easy pouring. Mix the ingredients up and dump into each bag, sealing them, making sure to remove as much air as possible.
If one of your bottles of condiments is running low, tip it upside down in a cup while you work.
If you're going to freeze these, the best way I've found to get the extra air out of the ziplock bag is to fold the top of the bag back over the roast and as the marinade sneaks up to the top, seal it with as little air trapped inside as possible.
You can opt to let these sit in the bags overnight to marinate the meat prior to cooking or freezing, then when you take them out to use them, you'll be sure the flavors have had some time to meld (since Instant Pots cook very quickly this can be helpful when using that cooking method).
Last, but not least, if freezing these, make sure to position them in the freezer so they don't become frozen TO any wire baskets or dividers you may have.