Hello Jean-Pierre,
Cooking for someone with a food allergy can feel daunting, but you can definitely make a fantastic, safe satay sauce without peanuts, and it does not have to be expensive.
The best and most affordable direct substitute is sunflower seed butter (often labeled as SunButter). It is completely nut-free, reasonably priced, and has a rich, roasted, savory flavor that mimics peanut butter almost identically in sauces. You can substitute it at a 1:1 ratio in your favorite satay recipe alongside coconut milk, soy sauce, garlic, ginger, lime juice, and a bit of brown sugar.
Another very economical choice is tahini (sesame seed paste), assuming the person is not allergic to sesame. Tahini blends into a wonderfully creamy sauce with a deep, toasted flavor. Because tahini is slightly more bitter than peanut butter, simply balance it out with a little extra brown sugar or sweet soy sauce (kecap manis) and an extra squeeze of fresh lime juice.
If you want the cheapest option possible, you can also purchase raw shelled sunflower seeds in bulk, toast them in a dry skillet for a few minutes until fragrant, and blend them in a food processor with a touch of neutral cooking oil until smooth before incorporating the rest of your aromatics.
I hope this helps you prepare a wonderful and safe dinner with your air fryer.
