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Ruthy is a Recipe Tester for Food52
If your protein (beef, sausage, etc) is fully cooked, it should be okay to assemble today, keep covered and chilled in the fridge, and bake tomorrow. Especially if you're using no boil noodles, there's not as much chance of possibly getting mushy noodles from sitting too long.
I agree with Ruthy, though either solution will actually work. My preference would be to bake today and reheat tomorrow. Only because as with many of these types of dishes, the flavors improve with a nights stay in the fridge after cooking.
Most recipes for lasagna contain eggs mxed into the ricotta cheese filling. Even if this recipe doesn't include cheese, there are food safety dangers if some components fall within the 40-140 degree danger zone for bacteria growth. Are the sauce, meats, vegetables, cheese all chilled below 40? People get into trouble when the mix hot components in with cold, and bring the dishes temperature into the danger zone. The best advice is to cook this now, rapidly chill it once fully cooked, then refrigerated. You cant ever go wrong with this advice and you dont have to think about any other variables.
And again - the critical issue is NOT if items are cooked or not prior to refrigeration. The issue is the current temperature of the items prior to refrigeration and the duration of time they have remained in the 40-140 degree danger zone. I see a new great post on food safety here on food52 that everyone should read. Within just a few hours in the danger zone millions of harmful bacteria can manifest in your food.
Pastas, sandwiches, salads, oh my!
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