Easy & Delicious Ranchero Beef and Potatoes Dinner

Ingredients
1 to 2 Pounds of chuck roast
1 Tbsp olive oil
2 garlic cloves
1 large potato or two medium potatoes
1 poblano pepper
1 med onion
1 tomato
1/2 8oz. can tomato sauce
1/2 Tbsp ground cumin
1 tsp black pepper (adjust to taste)
1 1/2 Tbsp chicken bouillon or 1/2 Tbsp salt (adjust to taste)
1/2 Tbsp mexican oregano
3/4 of a cup of water
Small bunch of cilantro