1 c. oil (Canola, Olive or other)
1 tsp. Dijon mustard
1 egg
2 tbsp. vinegar or lemon

Put mustard, vinegar and 1 egg into blender. Blend together on low for a minute or less. Take oil and pour into blender very slowly while running it on slowest speed - just a thin trickle of oil. Result - mayonnaise - homemade.

If ingredients can't coagulate, pour contents out of blender. Crack one more egg into blender and very slowly while blender is on lowest speed, pour ingredients back into blender. Keep refrigerated and use promptly.