A fellow farmer sent us a celeriac tip: celeriac braised in butter.  Braise one celeriac cut into matchsticks in a 12-inch nonstick sauté pan with enough acidulated water (3 Tbsp. lemon juice and 1 tsp. salt to 1 quart of water) to cover, salt, pepper, and 1/2 stick butter, approx. 30 mins., until water evaporates and celery root is tender.  Do not let brown.  If not yet tender, add more butter and continue to stew until tender. You could dress this with tarragon vinegar, lemon juice, or Dijon mustard, or leave it plain