Suppose someone is making a huge 50-gallon vat of cholent. Accidentally, an entire bag of milk breaks and spills into the cholent. There is more than 60x as much meat cholent as there is milk, so the milk should theoretically be batel b'shisim. But does the fact that a non-negligible amount of milk fell into the pot (as opposed to a couple of drops into a smaller pot) change anything?
The Rambam (MT Ma'achalot Asurot 9:10) writes
If the milk fell into the sauce or onto all the pieces and it was not known on which piece [the milk] fell he should stir the entire pot so that all its contents will be mixed [thoroughly]. If the flavor of milk [can be detected] in the entire pot, it is forbidden. If not, it is permitted. If a gentile to taste [the pot] whom we can rely on cannot be found, we require a measure of sixty whether for meat in milk or milk in meat. If there is one measure in sixty, it is permitted. If there is less than sixty, it is forbidden.
Therefore mixing the pot up to the point that the milk is dissolved into the mixture is enough to make the cholent kosher as long as there was 60 times the quantity of milk and if you cannot identify the milk anymore.
I will try to redefine the question. Generally Halacha tells about a drop of milk that falls in a pot of meat.e.g. Mishna Chullin 8, 3:
ח,ג טיפת חלב שנפלה על חתיכה--אם יש בה בנותן טעם באותה חתיכה, נוער (יש גורסים ניער, וזה מדגיש דווקא בדיעבד ועיין ערוך השולחן סימן מ''ב סעיף ט''ז סיכום יפה של הנושא של ביטול איסור לכתחילה במקרה זה) את הקדירה; אם יש בה בנותן טעם באותה הקדירה, אסור.
In such a case we must not evaluate if the quantity added by the isur leads to a gain. So the bitul is only done to avoid a loss.
But when the quantity of isur actually present in the pot is valuable, e.g. it adds a piece to the meal, is it permitted to eat the extra piece of Tshulent.
There is halachot about this when solid pieces of Isur are mixed with Heyter, e.g. Teruma 5, 7:
ה,ז סאה תרומה שנפלה למאה, הגביהה ונפלה אחרת, הגביהה ונפלה אחרת--הרי זו מותרת, עד שתרבה תרומה על החולין
A din for Teruma, to extract the same quantity from the mixture.
See Chullin 100a, see SA YD 109.1.
But here, the milk is allowed 100% because it's not able to give a perceptible taste in the meat (to prohibit we need taste of milk in the meat and taste of meat in the milk. See Chullin 111a). So, paradoxally we have allowed milk in the pot and allowed meat, even if the quantity of milk is great, there is no hanaa from bitul Isur, because no prohibited foods have ever been present. (This is different conceptually from the case in which a non Casher meat was annulled. See here the explanation of the Mahari Ben Chaviv).
See Gemara Chulin 108a, and Rashi paragraph "Amar Leh Rava".