I originally got this recipe for 'navets persilles' from the Julie/Julia project. In the original the turnips are par-boiled and then cooked again for 30 minutes. I don't usually blanch the turnips before boiling them, and I find they usually cook in less time (especially if they are fresh from the garden and not the hardened, wax-coated things you find in the store). Nowadays I make this more frequently with cauliflower than turnips, though I think any dense vegetable would work. Parsnips, celeriac, carrots, etc... It's so simple it barely calls for a recipe.
3-4 c. of a dense root vegetable or cauliflower, in chunks
salted, boiling water
3-4 Tbsp. butter
freshly ground black pepper
Aleppo pepper flakes or paprika (optional)
Boil the vegetables in well-salted water until tender. Toss with the remaining ingredients. Be careful with the lemon juice, so you don't add too much--usually one half of a lemon, gently squeezed, is enough.