Soak tamarind in hot water to soften, squeeze between fingers, strain, reserving the juice. Discard seeds and whatnot. Set aside.

Make paste of oil, water, onion, garlic, and ginger, dump into non stick pan, add in galangal, coriander. Stir fry til bubbly and then dump mixture onto beef cubes, followed with tamarind juice.

Coat beef and cover with cling wrap. Marinade for at least 45-60 minutes. Thread beef cubes onto skewers.

Grill until cooked, turning skewers occasionally for even grilling.

Slice shallots, chilies, and tomatoes and place them into a bowl.

Flavor mixture with lemon juice and soy sauce, with a little water (1/4 c increment).

Serve satay with the sauce, either as is or with warm rice and salad such as cucumbers with lettuce