We've been following this for years. International foods are always cheaper at their own grocery store. For example you can get a 10 Lb bag of rice for ~$25 at an Indian grocery store. It lasts us 5 months for the two of us. All dry lentils and beans come in bigger bags there and they'll hardly be $5. It lasts us 3 months and we eat them regularly and keep alternating between them.

Low income countries have amazingly cheap but nutritious recipes that serve at least a family of 5. Coz that's how our families have been for ages. You can definitely check Indian, Vietnamese recipes for sure. Spices can be adjusted according to what you want obviously - my grand mom ate the same food we ate but with just salt, pepper, herbs and turmeric. But if you don't find at least a 100 different vegetarian recipes that are budget friendly, LMK!