Given the background description of some cooking related query, summarize the question into a title
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Question: I've been making freezer burritos and eating them for lunches this week. The first batch I made microwave beautifully: just 45 seconds and they're hot all the way through. They were layered with rice, beans, and corn, nothing else (I don't eat cheese and I wanted them to be non-spicy so I can eat them when I'm feeling unwell). The second batch replace the corn with ground beef, cooked and seasoned. The exact same beans, the same rice made the same way. They're smaller, due to using a different package of tortillas; after almost 2 minutes of heating in the same microwave, the meat burrito I had brought still had cold spots in the middle. What causes this? Can I avoid it somehow? Should I mix the ingredients instead of layering?

Answer: Why do my meat burritos not heat well?


Question: I am often making a basic leavened bread for some basic recipes, like naan, burek, focaccia, pizza, etc. However, I find that dry active yeast is prohibitively expensive, considering it is a self-replicating living organism. Is there a way to effectively create and store yeast for a reasonable period of time (~3 months) from a mother spore?

Answer: How can I cultivate and store yeast?


Question: Today I sauteed a quarter cup mushrooms in 3 tbsp butter and added 250ml cream. Everything was set for me to add the ricotta and finish the Alfredo, but it only partly melted. Beyond a certain point, there were some "cheese crumbs" that no amount of heat could dissolve, thus robbing me of a velvety textured Alfredo.I have successfully made Alfredo with ricotta cheese before. Is there any reason as to why the ricotta did not completely melt? The ricotta package was only opened a few days, so it couldn't have gone bad.

Answer:
Why did my ricotta cheese did not completely melt in the Alfredo?