A long time ago, I spent several months in France. Twice I flew to England and took a combination of buses, ferry (way before the chunnel!) and trains to Lisieux, in Normandy, and later Tours, in the Loire valley. I was in college at the time and was an extraordinarily picky eater. But those months spent eating seasonal fruit, meat from the semi-weekly market and delicious bread cured every last food aversion I had.
One such aversion was to salad dressing. On the rare occasions that I would eat a salad, I topped it with nothing but salt. During my second trip, which was to Tours, I lived with a family. Dinner each night ended with a simple green salad and cheeses from the week's market trips. Those salads were always the same and always delicious.
To make the dressing, start with shallow bowl. Add a small teaspoon of brown mustard, a clove of chopped garlic, salt and pepper. Mix with a soup spoon of red wine vinegar. Add three to four soup spoons of canola oil one at a time. Mix very well after each addition so the dressing emulsifies properly.
It's also good with tomatoes. You'll want a loaf of crusty bread to sop up every last bit from the plate.