My wife is Colombian, so rice and beans is really big in our house. At our local grocery store, the beans and rice are even cheaper in the bulk bins than on the shelves. We can get two pounds of dried beans for less than $2 and same with the rice. Cooking up those beans with a few tomatoes, onion, cilantro, garlic, and spices on the stove will last us a week for dinner with the rice. Lentils are also one of our go to meals. They are a little more expensive at our grocery store in the bulk bin (~$1.50/pound), but we cook them up similar to the beans with tomato, onion, carrots, garlic, and spices served over rice. A couple of pounds of dried lentils will last us all week for dinner. I'll usually cook up a side of vegetables of whatever is on sale too.
Another meal we love to do is chickpea tacos. We just buy the canned chickpeas (usually ~$1/can), drain them, and sauté them up with some spices until they're crispy around the edges. I also will make my own bread and rolls at home when we want them since a bag of flour is so much cheaper than buying loafs. We will use the rolls to make a batch of pot pies and I use this recipe
https://minimalistbaker.com/1-hour-vegan-pot-pies/. I don't make them vegan. I use regular milk instead of almond milk and I make my regular biscuits.
We always eat smoothies for breakfast (lately it is banana, strawberry, a tropical frozen fruit mix, kale, several tablespoons of ground flax meal, and flax milk) which I'm pretty sure is usually our most expensive meal of the day lol, and then for lunch I just tend to eat some roasted veggies or fruit. If we have sweets, I usually make cookies or brownies for the week.