Pick the goal: creamy hot cereal (choose semolina/cream of wheat or oat flour) or thickening (choose rice flour slurry or all-purpose flour).
Start with the table ratio and use cold whisking for flour-based options to prevent lumps.
Heat and stir constantly for the first 60-90 seconds, then simmer until your texture matches farina (smooth and spoonable).
Adjust thickness: add a splash of warm liquid if too thick, or simmer 1-2 minutes more if too loose.
For best mouthfeel, keep stirring as it thickens—most substitutes set faster once they’re hot.