How do I cook this beef cut?

Looks like a chuck/bottom round.  Your best bet would be either to make a stew, or braise it (cooking low and slow in liquid in your oven).

Stew: Make beef Bourginon.  All you need is an onion, a couple carrots, and some cheap red wine.  Cut that thing into bite size pieces.  Cook in your pan and season with salt and pepper (liberally).  Remove meat.  Mince your onion, and then throw your onions into the pan and cook for 5-10 minutes.  Add 1-2 cups of red wine, stir and add your meat back in.  Then peel & cut your carrots into bite-size (1 inch) pieces and add them in.  Cook on low for 2-3 hours, stirring occasionally.

Probably chuck, and if so, the 'London Broil' cooking method - London Broil is a way of cooking, not a cut - will not be good enough for this to come out tender. This needs much more cooking time, in liquid, and at a lower temperature.

You will need seasoning beyond the basic salt and pepper to have more flavor, but it will do if that's all you have.  Some beef bouillon will help make a nice broth. Cooking with vegetables is an absolute must.

I made a chuck roast a few days ago. I coated the meat thoroughly with thyme, garlic powder, black pepper and paprika. I have been cooking for long enough that I can eyeball my spices, but you may want to measure. Do one side at a time. For each side, 1/2 teaspoon each of all four, and rub them into the meat after sprinkling on.

Place the meat in a deep baking pan. Add enough liquid, starting with one cup of red wine, to come halfway up the meat.  Cover tightly with foil and roast in the oven at .300 for two hours.

In the meantime, cut up your vegetables. The big three are a must, Onion, carrot and celery. Fresh or minced garlic, if you have it, can go in with these vegetables.  If there is room, potato wedges can go in.  As they cook, they absorb the blended flavors of the meat and other vegetables. If not, if you want potatoes, you can bake or make mashed.

After adding the vegetables, cover again, tightly, and roast at .300 for another two hours.

I roasted my chuck for six hours, three and three, but it was larger than yours - about four pounds - and I started with frozen meat.  However, as long as you keep it tightly covered with enough liquid, another hour won't hurt if after four hours, the meat doesn't feel fork-tender.

Looks like a "London broil" to me.In any case,I think if it were cut into chunks it would make a fine stew.(recipes available everywhere).

It looks like chuck roast.  Take your filet knife.  Sharpen the tip. Put about 25 small holes in each side. Next lightly salt. Then rub a ripe mango into both sides. Let set 2 to 3 hours. Then bake with Plantans, baking bananas in brown sugar. & butter in the grill. Also a potato goes well. Mango rubbed in will make it tender. Do not let set over night with mango rubbed in. It can make meat turn to mush. 

Looks like chuck -- a sub prime cut, from the shoulder, not so tender, fabulous flavor.  That white stuff is fat and very tough whatever -- lose that part.

I use chuck for four recipes, I use one pound for three servings:

Stew -- 3/4" cubes, flour, sear in butter, add 1+ cup of chopped onion and 1+ cup of chopped celery and half cup of chopped mushrooms. Once limp, pour in a 12 ounce bottle of porter beer and let it simmer dead low for 3 hours. Add a little water, and carrot, 15 minutes add potato, 15 minutes add parsley and basil, 15 minutes a little corn starch to thicken up.

Cornish Pasty -- 1/4" cubes, sliced carrot, chopped potato, chopped onion, frozen peas, parsley, basil, Lea & Perrins, wrap with a pastry and bake for 75 minutes.

Slice in 2" x 3/4" x 1/8" strips.

Stroganoff -- onion, 12 ounces mushroom, secret sauce, serve over egg noodles.

Pepper Steak -- fresh ginger (I see behind your beef), garlic, soy sauce, marinate for an hour, brown in olive oil, add green onion, celery, bell pepper, roma tomato; serve over rice.

Without actually being there, it kind of looks like a London Broil-which is actually Not a cut of meat, rather a way of cooking it. 

Assuming that is what it is, I would marinate it for a couple of hours in a vinegar based dressing, like a standard Italian dressing and then grilling it. Slice Thinly across the grain and enjoy-BUT it Will tend to be a bit tough. 

I generally do not buy London Broil, unless it is on sale, as I would use it for a stew-braised for a Long time in a liquid. That way it would break down and get tender. 

what did the package say the cut was? 

with an unknown cut like that I would probably make a Beef Stroganoff 

Slice the beef thin, against the grain. 

Sauté some onions and mushrooms. Remove them from the pan

Sauté the beef. 

Add the mushrooms and beef back to the pan.  

Sprinkle in some flour and cook that a bit. 

Add some beef broth to make a gravy

Add some sour cream, do not let the mixture boil after you add the sour cream

Serve over noodles, rice or with mashed potatoes. 

Cook onion's, garlic and ginger in oil and butter..... put in orange and lemon skin...

add spice's like clove's or seed's, celery seed's  what ever your flavour is... add juice from orange...

Throw your diced meat in, salt,... cover it in spice's... dont over heat... add more juice while cooking... and a teaspoon of raw sugar, put in coconut milk or cream...

simmer untill cooked....

taste's nice with mash potatos "and" salad.... easy....

Not sure exactly what type meat it is, but looks like beef. But you could put it in oven with bout 2 cups of water and use some meat seasonings over it with some onions and carrots and potatoes and make a stew out of it